Читать книгу The Lost World MEGAPACK® - Lin Carter - Страница 43

LAND OF THE SHADOW DRAGONS, by Eando Binder

Originally published in Fantastic Adventures, May 1941.

The chartered plane’s motor roared as it left Chicago’s Municipal Airport. A low-winged cabin ship, it raised sluggishly, loaded almost to capacity with crated supplies.

Pilot Hugh Crane tensed at the controls. The ship was acting almost as though it were overloaded! He gunned for altitude desperately. Far down the field were high-tension wires. Once a plane had blundered into them, ending up a broken, burning mass of junk.

Why wasn’t the plane rising normally? The motor hummed smooth as silk and Crane had full control of ailerons. Yet the craft inched itself from the ground with agonizing reluctance.

The suspense was over in seconds. The plane barely cleared the wires. The margin had been uncomfortably close. If the undercarriage had not been retractable, the ship would have crashed.

Crane unclamped his lower lip from his teeth. In his years of piloting, he had never come that near to disaster. But now the plane slanted up into the safe aerial highways.

He turned to his two passengers wondering if they had noticed.

“Rather a poor take-off, wasn’t it?” Paul Harlan said sharply. “We were careful not to overload the ship, according to airport instructions and inspection.”

Crane knew he wasn’t going to like Harlan. Tall and dark, he seemed about Crane’s age, under thirty. His bearing was stiff and cold, his lips straight and thin. A man who would play his own game, given the chance.

Ignoring the words, Hugh Crane addressed the girl in the side seat. “Where to, Miss Damon?”

She did not reply at once.

Dawn’s glowing red arc brightened in the east, revealing the girl more clearly. Crane’s brief glance formed a staccato impression. Figure tall, slender. Features regular except for a slight upturned nose. Type, titian blond. Clothing mannish for roughing it—boots, leather breeches, suede jacket, tam o’shanter. Total effect, not bad!

“You will fly due northwest,” the girl directed. Her tone was preoccupied.

“To what, or where?”

“Our destination is near Great Bear Lake, Canada.”

“Which side of it?” Crane pursued. A frosty stare accompanied the girl’s response.

“As I told the airport officials, that’s my business. I paid for the privilege of having an uninquisitive pilot!”

“Ouch!” Crane said mentally. What kind of trip was this? Why all the secrecy? He took a longer look at the girl. No, she wasn’t just a wealthy madcap, out for a lark. There was quiet purpose in her hazel-brown eyes. Almost grimness.

“I can’t go by those general directions,” Crane ventured. “Not all the way. A plane isn’t something you can amble around in aimlessly. After all, Miss Damon—”

Jondra Damon interrupted with a toss of her head.

“You’re being difficult. When we reach Great Bear Lake, I’ll give you more specific instructions. If that doesn’t satisfy you, turn back! I’ll get another pilot.”

For a moment they glared at each other. Then Crane shrugged and turned eyes front. The girl was within her rights. He had been instructed to fly where she wished, within the range of risk to life and ship. Beyond that, the officials had said—or known—nothing of the eccentric arrangement.

What was it all about? Crane began to feel he was flying in some sort of mystery. To Crane it wasn’t exactly an unpleasant thought.

The girl’s hand touched his shoulder. She was suddenly smiling.

“I didn’t mean to be so abrupt. But I really can’t explain much more at present. My father is up there—Dr. Sewell Damon. He’s conducting experiments. Mr. Paul Harlan, who answered my ad last week for an experienced chemist, is to assist him. The exact destination is being kept secret as long as possible at my father’s request.”

She added, after a moment’s hesitation, “I think he fears—well, spies.”

“Spies!” Crane echoed the word with a start. “What sort of experimenting is he doing?”

The girl shook her head, but not angrily. Her eyes suddenly gleamed with worry. She spoke in a low murmur. “I think he may be in danger!”

She arose, as though to pace the narrow cabin floor.

“Sit down!” Crane snapped. Hastily he added, “Sorry, but it’s the best thing to do while flying.”

But before the girl could obey, the ship lurched through an air pocket. The girl seemed about to stumble and fall backward. But miraculously she didn’t, as if a hand had caught her arm just in time.

“Thanks!” she smiled at Harlan, gaining her seat.

Harlan stared at her blankly. He had had no chance to help her, half sliding out of his seat himself.

“What—” he began, but then shrugged. It was hard to talk above the drone of the propeller.

Crane’s quick glance behind him had taken in the episode. Again things seemed verging on the mysterious. First the plane, apparently overloaded. Then the queer mission they were on. Now the girl, acting as though an unseen passenger had assisted her.

But there was no such passenger. She had imagined that someone had helped her keep her balance.

* * * *

The plane drummed northwest. The countryside below became steadily more bleak and rugged with each degree of northern latitude.

Ten hours later, Hugh Crane turned to Jondra Damon, dozing in her seat. He hated to disturb her, but now was the time for directions. She looked like she hadn’t had proper sleep for a week, in preparation for this strange venture.

“We’re within a hundred miles of Great Bear Lake. Might tell me now exactly where you want to go.”

Jondra Damon rubbed her eyes. “Fifty miles east of Great Bear, directly on the Arctic Circle.”

Minutes later, a snow squall came up, chilling the heated cabin.

Crane pondered. “If the snow gets thicker,” he said, “I’ll have to land on the first level stretch. But maybe we can make it to your destination. What are we looking for? Any landmark you can name?”

“It’s a valley,” the girl responded shortly, lighting a cigarette.

Crane looked helplessly at Harlan.

Harlan shrugged. “I know as little about it as you do,” he grunted.

At the same time he eyed the girl as though he, too, resented being kept so much in the dark.

Jondra Damon blew out a cloud of smoke imperturbably.

“I thought it was women who were always curious. Now look, you’re both paid to do as you’re told, and paid well. You, Mr. Harlan, were hired at ten dollars a day to help my father when we arrive. You, Mr. Crane, were engaged to land the plane where I state, help unload the supplies, and then leave. It’s simple enough, isn’t it?”

“But the valley!” Crane said patiently. “I presume there’s a big sign somewhere saying valley in big red letters?”

The girl flushed. “Oh! Well, it’s a sunken valley. Father informed me that it should stand out from the air by itself.”

Crane shook his head, but went back to his controls.

Reaching Great Bear Lake, he cruised over its eastern shore, and swung gradually away in a wide circle. The snow thickened, making a landing imperative within an hour. Crane swept his eyes from horizon to horizon for the valley. A sunken valley. What in the world would it look like?

A hand gripped his shoulder suddenly, turning him slightly. Then Crane saw it himself—a dark gash in the general whiteness of snow-tufted land.

“Yes, that must be it!” Crane said, wondering why Harlan was so mysterious, grasping his shoulder and not saying a word. He looked around, but Harlan was now beside the girl, peering down.

What was the man’s game? Crane thought fleetingly. Had he known how the valley would look, despite his pretended ignorance of the whole thing? Was he keeping things from the girl, as well as the other way around? What was in that valley—gold, radium?

He’d soon find out. Crane zoomed for the spot. Circling and lowering, he made out the barren floor of the valley, with only an evergreen here and there. A landing could easily be made in the valley itself. It was sunken, all right, at least three hundred feet below general level, with sheer cliffs at every side.

“How queer it looks!” Jondra Damon was murmuring at his side, peering through the windshield. “Watch out for the snow…”

It struck Crane too. Swirls of snowflakes dropped into the valley and seemed to hang. Momentarily, they seemed to form the ghost-shapes of tall trees. Crane felt a qualm of uneasiness, but quickly killed it. One could see anything in clouds or snowstorms, with a dash of imagination.

“No time to waste,” he warned. “We’re going down. Hold on!” Heading into the wind, Crane slanted down for the broad, smooth area at one end of the valley. There should be no trouble.

Suddenly a tiny figure emerged from some hidden shelter below, near a cliff-face. It ran madly into the open, swinging its arms wildly.

“It must be father!” Jondra cried. She peered closely. “He seems to be warning us away. I don’t understand, there’s something wrong!”

Harlan gasped. “The man’s mad! He’s firing his gun at us!”

Above the roar of the propeller sounded the sharp bark of a rifle. The man below was firing not at them, but in warning not to land! To stay away!

“I’m going to land anyway!” Crane yelled. “I’ve got to! Blinding snowstorm up above, and getting worse. This is a safer chance.”

A hundred feet above ground, Crane gasped through tight-pressed lips.

Something had brushed against the undercarriage! He felt it jar through the ship, though he saw nothing! A keen instinct of danger knifed through him. He tried instantly to zoom upward again, but again something struck the ship.

This time it had been at the right wingtip, almost wrenching the wheel out of his hands. The plane dipped groundward sickeningly, like a wounded bird. With desperate strength, Crane straightened the craft just as the wheels touched ground.

Bouncing badly, the plane rumbled over the rough terrain. It rolled almost to a stop, but abruptly struck something with a stunning impact, shivering through its entire length. Crane found himself thrown in a tangled heap with his two passengers on the tilted cabin floor.

The motor coughed to silence, luckily, eliminating the danger of fire if any gas had spurted out of the wing tanks.

CHAPTER II

The Invisible Specter

Hugh Crane picked himself up dazedly, then pulled the girl to her feet. She lay limp in his arms for a moment, half stunned. Finally her eyelids flew open. The warm color of her eyes was washed over with terror that faded, and wonder that grew.

“What happened?” she asked weakly. “Why did the plane act as if it had struck something?”

“Struck something!” Paul Harlan stood beside them, dark face glowering, a bruise over his right eye. “Bad piloting, that’s all,” he growled. “First he nearly wrecks the ship in taking off at Chicago. Now he nearly puts us down in pieces!”

His voice rose harshly. “Spies! Your father is worried about spies, you say. I just wonder if this Hugh Crane is a licensed pilot at all. Or if he’s using his right name!”

Jondra Damon’s eyes widened. She stepped back from Crane.

“Father warned me to be very careful, and now—”

“Good God!” Crane exploded. He’d had to bite his lips to keep from swinging at Harlan. Now the stark suspicion in the girl’s eyes added fuel to a mounting rage. He didn’t have to take this from anybody!

He lunged at Harlan, driving his fist forward.

The blow never landed. Crane was not quite sure why it didn’t. Some force seemed to grasp his wrist and hold his arm back. He tried again, more enraged than ever.

“Stop!”

Crane whirled. The new voice had come from the swung-open door of the plane’s cabin, with a bark of authority. A man leaned there, rifle upraised. Tall and thin, gray-haired, unshaven, boots and pants muddy, he looked the part of some desperate character. But there was intelligence in his high brow and level gray eyes.

“Dad!”

With the one word, Jondra flew to embrace him. He patted her head, then disengaged her gently, facing the two men again.

“I heard your little quarrel,” he said casually. “Your nerves are upset by the close escape you had. Calm down, please.”

Crane relaxed, anger draining from him as suddenly as it had come.

“You’re Dr. Sewell Damon, of course,” he said, and introduced himself and Harlan. He went on, grinning ruefully, “I was supposed to just land, and unload, and go. But I guess now I’ll have to stay till I can make repairs.”

The scientist’s lips pursed behind a week’s growth of beard.

Crane snapped, “If you think that’s a spy’s trick, so that I can stay and horn in on whatever you’re doing here—” He shrugged indifferently.

Dr. Damon’s eyes narrowed. His hand tightened on the rifle.

“If there’s any spying, it wouldn’t be healthy. The secret of this valley—”

“I don’t want a dime of it,” Crane growled. “Just tell me one thing—what spoiled my landing? Bad air-currents rising from the valley?”

Dr. Damon stared. “You haven’t guessed?” he said slowly.

“Guessed what?” Crane looked blankly at Harlan, who was equally mystified.

The scientist turned. “Follow me.” The four stepped from the cabin. Dr. Damon dodged under the right wing and stood erect beside the motor cowling. There was a large round dent in the front wing-edge. Crane gaped at it.

“Exactly as though I’d struck a tree there, just before the plane stopped rolling.”

“You did,” Dr. Damon said.

“What? Where’s the tree?” Crane looked around for the fallen tree, but there was no sign of one within hundreds of yards. “Look, Dr. Damon,” he grunted, “I’m not in the mood for humor—”

A startled cry from Harlan interrupted. He had passed back of Crane, stretching his cramped muscles. Now he was toppling to the ground, for no visible reason—as if his legs had been knocked from under him!

Rising to his elbow, looking foolish, he slowly stretched out his hand near the ground. Crane watched in utter fascination as Harlan’s hand seemed to meet something, and explore its outline. Harlan looked up with his foolish expression altered to one of ghastly shock.

With a smothered curse, Crane kneeled and stretched out his hand to the same spot. In mid-air he felt something—the bark of a tree! Solid and real to his sense of touch, but unseen by his eyes.

Harlan’s whisper seemed to shatter the quiet air.

“It’s—invisible!”

For a moment nothing more was said. The three newcomers to the valley looked at one another in dumb amazement, as human beings must when confronted by a wonder out of the realms of fantasy. Invisibility! A dream of science—and of superstition before that—come true!

Hugh Crane followed the length of the fallen trunk before he was satisfied. With his hands he felt the bole, the lower branches, and the upper foliage of some pine-like tree with needles and cones, knocked over by the plane.

He came back facing the scientist.

“So that’s the secret of this valley, Dr. Damon! Not gold or minerals, but invisibility!”

The elderly man nodded slowly.

“It’s a miracle that you landed without smashing up completely.” He swept an arm around. “The valley looks bare to the eye, doesn’t it? As a matter of fact, it teems with life! Trees, bushes, grass and animals. All invisible!”

The others looked around. The level stretch of the valley floor was naked, to their eyes. Yet they realized now that between them and the cliffs must be a thousand unseen things. Jondra shivered. Crane could hardly keep from doing the same, overwhelmed by the eerie mystery.

Dr. Damon resumed. “By blind, lucky chance, you brought the ship down in a cleared patch of bush growths. Almost any other spot you would have cracked up against rows of trees.”

“Fools luck,” agreed Crane. “But why weren’t we warned?”

“I tried to warn you away,” the scientist reminded. “I fired my gun, hoping you’d go back and land up above somewhere.”

“But why wasn’t your daughter warned, before we even arrived?” Crane eyed the man accusingly. “You risked your daughter’s life by keeping that so secretive!”

“No, I was told,” the girl spoke up. “That is, father mentioned invisibility in a message to me. But he didn’t tell me the whole story—that the valley is crammed with invisible trees and life.”

“I couldn’t,” Dr. Damon said gently. “You might have thought I was mad.” Then his voice sharpened. “But Jondra, I did warn you not to let the plane be landed in the valley, in my second message—”

“Second message?” The girl stared at him. “I didn’t get a second one!”

Dr. Damon whirled.

“Pierre!” he cried. “Didn’t you deliver my second message?”

Crane stalled as another figure silently stepped forth from the shadow of the plane. He had come up so quietly that the others hadn’t known he was there. Black eyes, sleek black hair, emotionless features and buckskin garments tabbed him instantly as a French-Canadian guide and a roamer of the north country.

“Pierre, my guide,” Dr, Damon informed them parenthetically. Then again he demanded: “The second message, Pierre. By heaven, if you failed to send it—”

“I send it,” Pierre protested in a hoarse, taciturn voice. “I mail it from Good Hope, t’ree week ago.”

“Then it was lost in the mails,” Dr. Damon sighed. “Well, things have been uncertain right along, since the war. Thank heaven you’re here safe and sound, Jondra. And you, Crane and Harlan. Sorry about your ship, Crane. I’ll pay for the damages.

“You can stay as long as you need to repair it. Plenty of food supplies came with Jondra. I have a comfortable cave-home in the nearby cliff. Well, you’re all probably tired and hungry. We can unload the plane tomorrow. Follow me.”

The night was coming on. The three who had spent a dozen hours in the air were ready for food and rest. And shelter. A chill wind swept down into the valley, protected though it was.

As Crane stepped away from the plane, a thought ground forward in mind.

“Who turned off the motor, just after the landing?” he asked aloud. “Harlan, Miss Damon and I were on the floor, helpless. You, Dr. Damon, and Pierre were approaching. It couldn’t be any of us.” He grasped the scientist’s arm. “There wouldn’t happen to be—invisible men?”

Dr. Damon started. “Not that I know of,” he vouched. “It’s a preposterous thought. Your motor died by itself.”

Crane shook his head. “I’d like to believe that. But the ignition key was turned off.”

“Then the jar of landing turned it,” Dr. Damon retorted. “Don’t let your imagination run away with you.”

Imagination? Imagination that the plane at take-off had been heavily loaded? That Jondra Damon had kept on her feet in the bouncing air pocket? That a strange force had withheld his blow at Harlan? That a shock-cushioned ignition key had been turned by a human hand?

All imagination? Or did it add up to some mystery, strangely linked with this phenomenal valley of invisibility?

Crane didn’t know. But he was determined to find out, one way or another.

CHAPTER III

Sabotage

Pierre and Dr. Damon led the way.

Harlan, Jondra and Crane followed in single file, carefully stepping in the exact path they broke. Blundering into an unseen tree would not be pleasant.

Dr. Damon kept one hand directly before him like a sleepwalker, for emergency, but seemed able to avoid invisible trees by some instinct. He stepped along sure-footedly, as did Pierre.

“From experience,” he confided, “I can make out the trees. They aren’t absolutely invisible. Nothing can be, except air and colorless gases. The trees throw a faint shadow that my eyes—and Pierre’s—have learned to watch for. With the sun setting, the shadows are longer and more definite. Do you see them at all?”

Crane gradually made out the faintest of shadows slanting over what seemed barren ground. Like eyes adjusting themselves to gloom, he could squint and bring them up slightly. He sucked in his breath. There were hundreds of those long, faint shadow-streaks. A whole forest towered around them!

A forest of trees as solid as the ground, but as vagrant to the eye as smoke. Light went through them with less hindrance than through glass. It was amazing, almost incredible.

The ground was not barren, however, upon closer inspection. A carpeting of dead needles lay decaying over the ground, as in any pine forest. Here and there they stepped over legs and fallen trees, completely visible. Dead branches and sticks were in the visible spectrum.

“This valley’s invisibility is confined solely to its living life-forms,” Dr. Damon explained. “When a tree or animal dies, it passes into the visible.” He stopped, pointing. “Look—a rabbit!”

Crane barely made out a faint trail of mist streaking across their path. Invisible animals roamed these invisible forest glens.

“There are also fox, deer, and I think bear,” Dr. Damon elaborated. “It—”

He was interrupted by a blood-chilling roar that sounded faintly from far across the valley. Both Pierre and the scientist jerked their heads, exchanged a glance, and gripped their rifles more firmly.

“Lynx,” stated Dr. Damon briefly.

“Are you sure it wasn’t anything bigger?” Crane asked. “I just thought I saw a shadow thrown momentarily across the far cliff wall, near where the sound came from. It was the outline of—”

Crane stopped. He had been about to say something preposterous.

“Lynx,” repeated Dr. Damon tersely.

Crane saw the scientist’s surreptitious glance at his daughter. He kept still. But the shadow aside, the roar itself had never issued from the throat of a mere lynx. Of that Crane was dead certain.

* * * *

A natural rock overhang formed the roof of Dr. Damon’s valley dwelling. It extended back fifty feet in the base of the east cliff wall, which was three hundred feet high. Logs set upright to enclose the sides of the rock pocket were of Pierre’s handiwork.

The space within was warm, dry, with a hard-packed floor. Pierre, with his kind’s resourcefulness, had also fashioned several items of crude furniture—chairs, tables and low bunks cushioned with pine needles. One new bunk had been added, obviously for Harlan.

“You hadn’t meant for me to stay, then,” Jondra said. “There’s danger here, Dad! You wouldn’t say it in the message, but there is danger. I can feel it!”

Already unnerved by the hazardous landing, the girl’s face was strained. It was not a light shock suddenly to see—or not see—a valley of shadow-things in an otherwise normal world.

“Danger of stubbing your toe!” Dr. Damon forced a laugh and chucked his daughter under the chin. “Food and sleep are what you need, all of you.”

Pierre had already begun boiling a stew of jerked beef and onions over a stone stove just outside the pine-slab door. They ate looking out over the now dark valley. It was not so eerie with darkness substituting for invisibility. The unseen forest creaked and rustled under a whipping wind from regions above.

Crane woke twice in the night, on his unaccustomed bed of pine needles. Pierre sat dozing before the smoldering fire he kept up against the night chill of the northern latitude.

But the second time Crane woke up, Pierre was standing erect, staring out over the valley of shadow-life. His expression in the firelight was strange—fierce and determined.

Pierre would bear watching too, Crane told himself. Had he delivered that second message, or not? If not, why not?

* * * *

Unloading the plane took the better part of the next day. Pierre, Harlan and Hugh Crane shuttled between the plane and cave with arms full, Pierre leading. Besides food supplies for an extended stay, there were crates of apparatus and chemicals.

Dr. Damon unpacked the latter eagerly, and set the items up on a long table previously made for the purpose, at the back of the cave. His laboratory workbench. Crane felt growing wonder at the array of test-tubes, flasks, hypodermic needles, morphine, alcohol and more complicated reagents.

“Now I’ll get somewhere,” the biologist asserted, rubbing his hands together. “Pierre wasn’t able to pack more than a few pounds of equipment here to me from the small town of Good Hope, northwest of here. I’ll have the answer soon.”

“Answer to what?” ventured Crane, nettled at the man’s secretiveness.

Dr. Damon’s gray eyes veiled themselves.

“How long will it take you to repair your ship?” he countered in a tone that meant, “How soon will you get out of my way?”

“I don’t know, probably a week or two,” Crane lied.

Brief examination had shown him that the ship could leave now. The motor was intact, also the fuel tanks. The left wing was rather badly ripped, and the undercarriage out of line, but with most of its former load gone, the plane would take off easily in the same cleared stretch they had miraculously landed in.

* * * *

The plane was ready to go, but Crane wasn’t. Not till he was sure Jondra Damon was in no danger.

He couldn’t leave a girl—any girl, of course—in the midst of unknown risks.

“You have a radio in the plane?” Dr. Damon said. “If you contact your airport, to tell them of the delay, I’ll trust you not to reveal this valley’s exact location. Name your price and you’ll go back with my bank draft—”

“No sale,” Crane snapped, angered at the cheap approach. He turned on his heel, aware that the scientist was staring after him with narrowed eyes.

He trudged to the plane, following the trail now marked with stones, winding through trees that he could feel with his hands in passing, but whose bulks were as transparent as air.

The wonder of it was somewhat subdued this second day. His thoughts revolved more around the undertow of human cross-currents gradually shaping themselves.

He passed Pierre on the trail, lugging a box on his broad shoulders. Reaching the plane, Crane stepped into the cabin. Harlan was there, and he turned with a startled air.

“The doctor’s supplies are all in the fuselage compartment, not here,” Crane said coldly.

Harlan’s shrug was studied.

“I suppose now I’m some sort of spy?” he retorted sarcastically. He stepped out to hoist a box to his shoulders, leaving.

Crane glanced around the ship. What had Harlan been doing? Then he saw…

When he left a minute later with the last box, his eyes were hard. He strode rapidly. He set the box down inside the doorway of the cave, and straightened with grim accusation on his face.

“Who smashed the plane’s radio?” he demanded, eying them one after another. His glance came back to Harlan. “You were there last, Harlan.”

“You’d have heard it if I did it,” Harlan returned easily. “I was just ahead of you—don’t you remember?” His eyes flicked to Pierre significantly.

Pierre’s beady eyes met Crane’s, then shifted.

“Pierre wouldn’t do it,” Dr. Damon declared quickly. “I know him too well.”

Crane ground his teeth.

“Someone did it! It was done between the time I talked to you last, and went to the plane.” He smiled grimly. “If Harlan and Pierre are eliminated, that leaves—”

“How dare you!” Jondra Damon blazed, stepping before him. “Neither Dad nor I would do such a thing. You could have done it yourself, since accusations are in order!”

Crane threw up his hands.

“I’m getting tired of all this!” he exploded. “That radio was our only emergency contact with the outside world, since the plane is damaged. Someone in this group smashed it, for reasons of his own. What’s more—” He stopped suddenly and ripped free a lath of the crate he had last brought. Reaching within excelsior packing, he drew out something by a handle and held it up.

“Grenades!” he hissed. “Potato-masher type. You say there is no danger here, Dr. Damon, yet you had your daughter bring rifles and hand grenades. Are the mosquitoes that big here?”

Jondra had shuddered at sight of the grenades She clutched her father’s arm.

“Why did you have me bring them? You must tell me!”

A swift, disturbed look came over the scientist’s face. Then he drew a smile over his features.

“You’re both being foolish,” he laughed. “The grenades are handy for any number of things, like blasting down trees.”

He turned away, in dismissal of the subject.

“All right,” Crane said calmly. “I’m going to repair the radio if I can. Then I’m going to signal the authorities and ask for an investigation. Something isn’t right here!”

He stamped back to the ship. In the cabin he sat down and waited, without touching the radio. The set was beyond repair. He knew that from the start. His threat, he hoped, would smoke out something. Far worse than groping through an invisible forest was this groping through undefined human purposes.

Who would come sneaking around now, to see if he was repairing the radio? Who was it that wished them isolated from the outside world—and why?

He tensed at a sound—the soft pad of feet under the wing outside. He slowly inched up till his eyes peered over the windshield ledge. Not a soul was there! Puzzled, Crane sank back.

The sound repeated itself & while later, just outside the cabin door. Crane crouched, waiting. When the sound was near, he rushed out, arms extended, ready to knock away a gun if the intruder carried that.

He gasped in chorus with a startled shriek. Jondra Damon was tight in his closing arms. Releasing her, he stepped back.

“You, Miss Damon? But—” Crane was more confused than at any time before.

Color flushed into the girl’s paled cheeks. And then suspicion leaped into her eyes. Crane was almost grimly amused. He realized his actions must be as queer in her eyes, as hers in his.

“Sorry,” he murmured. “Let’s call it quits between us. Frankly, I thought the one who had smashed the radio would show up, not you.”

“Thanks for the implication.” She answered his grin with a smile. “I came to ask you something—”

“Yes?”

Her hand touched his arm, before she went on.

“I trust you, somehow. I want you to guard my father, every minute of the day!” The words came in a rush now. “I feel his life is in danger. I feel there’s something in this valley—something horrible—that threatens him. Maybe all of us! Will you guard him for me, Mr. Crane?”

Suddenly she was in his arms again, but not by accident. He crushed her to him.

“Yes,” he whispered fiercely. “And I’ll guard you too—Jondra!”

She struggled free, her eyes wide, startled. She turned.

“Let’s go back to camp,” she said quietly.

CHAPTER IV

Ally Unseen

Jondra Damon hurried down the trail, Crane following. The redolence of pine forest was around them, and the rustle of branches in the wind. Almost, Crane could vision the trees themselves, and the girl tripping lithely through them. She glanced around once or twice, her hazel eyes glad to have him as an avowed friend in this queer adventure.

A hundred yards from the plane he caught her hand, striding beside her despite the danger of colliding with a lurking shadow-tree. He wanted to say something.

“Jondra—”

Crane was interrupted by an ear-splitting roar. They froze in their tracks. Then there sounded the crackling of undergrowth, and the lumbering of some form through the forest toward them!

Jondra cowered in his arms.

“Something’s coming at us!” she cried. “Something big—and invisible!”

Crane had already come to that conclusion. He shoved the girl ahead of him, back toward the plane. It was nearer than the camp. They sped as fast as they dared down the marked trail. Invisible bushes dragged at their ankles. Behind them sounded the heavy tread of some nameless beast, snorting and growling ferociously.

“If we could only see it!” Crane groaned.

But on second thought, perhaps it was better not to. No bear or tiger, or any creature Crane could think of had made the noises they heard. Its roar had come from a huge, rumbling chest. Its ponderous feet thumped against the ground with more than elephantine force.

In the name of the universe, what frightful monster was pursuing them, uncatalogued in any zoo or book on Earth?

Crane prodded the girl ahead faster, feeling blind and helpless. What chance to escape the invisible horror? Its growlings drew nearer, and imagination or not, Crane felt a hot fetid breath on his neck. Once it seemed to squeeze between two close-set trees. There was a crack, as one tree gave way.

Just as they reached the wing-edge of the plane, Jondra stopped short with a shrill scream. Crane saw it at the same moment—the ghostly shadow of the creature, cast ahead of them against the nearest cliff-wall.

Crane’s own mind and muscles turned numb. A mighty body reared in silhouette, at least twenty feet high.

Great triangular spines ran the length of it. Two thick legs pumped thunderously, upholding the body like a kangaroo. The short forelegs displayed claws that could rend apart an elephant at one stroke. At the end of a serpentine neck slavered huge ridged jaws of more than crocodile magnitude.

Unwisely, Crane shouted the one word to describe it.

“It’s a dragon!”

Jondra went limp with a little moan of utter terror, slumping against the wing-edge. Crane half swept her in his arms for a desperate run to the cabin, but released her. There wasn’t time. By the size of the shadow ahead, the behemoth behind must be within striking distance.

Sobbing in haste, Crane ripped open his jacket and drew out the masher-grenade he carried. He thanked his stars for suspecting he might need it, after discovering he’d brought them here. He gripped its handle, facing the oncoming beast.

If he could only see to throw!

Pulling the pin, he flung it blindly, judging as best he could by sound and instinct where the creature was.

There was a dull roar as Crane flung himself over the girl’s form, head down. A second later he heard the majestic crackling of a shattered tree, toppling and crashing its length through the other pines. Branches whipped across his pilot’s uniform, bruising him through the fabric. The tree had very nearly smashed down on them.

The grenade had done that—blown down a tree. But had it stopped the beast? The monster’s roar had echoed the explosion.

And now the beast’s bellow sounded again—nearer and utterly enraged. Crane had missed! In another second ferocious jaws would crunch through him and Jondra, snuffing out their lives. Crane winced, waiting for the death stroke.

He wasn’t sure what happened then. The whole sequence was a blur of sound. He seemed to hear a second grenade explosion, just after his own, clipping off the beast’s angry roar. And then from its throat issued a scream so piercing that Crane quivered as if stabbed.

Head ringing, he could hear little more. He sensed that the beast had gone. Picking himself up dazedly, he looked around. But he could see nothing!

That was the ghastly part of it. He couldn’t see the fallen tree, or the retreating monster, or any sign of the explosion save a swirl of settling dust. It was like a nightmare. Figures suddenly catapulted through the dust clouds, shouting. Dr. Damon was in the lead, with a grenade, Harlan and Pierre behind with rifles. Pierre shaded his eyes and stared down the valley, evidently at the fleeing beast.

Dr. Damon picked up his daughter, rubbing his cheek against hers, muttering.

“So, that’s what the grenades were for!” Crane hissed. “Why didn’t you warn us that dragons run around loose here? You pretty nearly fed Jondra to them, you old fool!”

“Let me explain,” Dr. Damon said tiredly. He eased the girl back, and continued.

“Six months ago I trekked with Pierre past Great Bear Lake, for firsthand glimpses of Arctic life-forms. I’m a government biologist, retired. We stumbled into this valley. It’s almost undetectable from ground level. I doubt if any white man has ever been here before. We almost fell into it before we knew it was here.”

He went on, as though finally aware he must tell the whole story.

“We circled the cliffs and found one spot where you could climb down, at some risk. Finding the astounding phenomenon of invisible life-forms here, I decided to stay for a study, sending Pierre back now and then for pack supplies. Finally I sent the message to Jondra, for more material, in order to make a more permanent stay.

“My idea was simply to have the supplies delivered, and then Jondra would return with you. I didn’t want to tell of the dragons, for then she would either insist on staying with me, or worry herself to death back home.

“I still hoped, after the bad landing, that that you would repair the ship and leave with her before the dragons became evident. I was only trying to keep it all from Jondra, for her own peace of mind.

“Not knowing you, Crane, I couldn’t tell you either and be certain you wouldn’t tell her.” He gulped for breath and went on. “So now you know the final secret of this valley. If there’s been any mystery about all this, it’s cleared up now.”

“Is it?” challenged Crane. “I’m not so sure.” He shrugged. “Anyway, I begin to understand a few things. Thanks, Dr. Damon, for tossing your grenade in time.”

The scientist stared. “I didn’t throw one. I wasn’t near enough to, before it was over.”

“Then who did?” Crane asked slowly. “I could swear my grenade missed the beast. A second one went off immediately after, chasing the beast away. Didn’t you hear two explosions?”

Dr. Damon shook his head, Harlan and Pierre following suit.

“We heard one explosion, then a tree trashing and the beast screaming. There was so much confusion of noise that you merely imagined you heard another grenade.”

“Take the credit due you,” Harlan said dryly. “Your grenade did the trick. You’re a hero.”

Crane ignored the sarcasm, but started a little, meeting Jondra’s eyes. She had come to quietly. There was no sarcasm in her eyes, only a deep silent thanks that made him turn away, flushing.

The girl sat up. “I heard every word you said, dad,” she stated, “about the dragons. If you’re staying, so am I.”

Dr. Damon looked at Crane helplessly. That was that!

* * * *

Back at the camp, the excitement over, Crane addressed the scientist while they ate their evening meal.

“Why not explain the rest, Dr. Damon?” he suggested. “What experimentation are you carrying on? And why have you wanted the valley’s location kept secret from public channels? I think Harlan and I are entitled to know.”

The scientist stiffened, as though to refuse. But when Jondra touched his arm, he relaxed. He smiled self-consciously.

“I suppose I have the foibles of any scientist who has stumbled on a great thing. This is one of those phenomena that crop up only once a century. If the world heard about it, a hundred biologists would be swarming up here overnight.

“Can you blame me for wanting to keep it to myself—for a short while anyway? Studying it, recording data, and then announcing it in one grand moment?”

Crane smiled. All his suspicions of Dr. Damon’s motives vanished in a flash. He was simply a scientist-miser with a bag of gold, figuratively. He had heard before that, contrary to general belief, scientists were often childishly jealous of their individual discoveries, and loved the limelight as well as any other human soul.

That took care of the scientist. But what of Harlan? And Pierre? Why had they acted strangely at times?

Crane temporarily shelved the matter.

“What accounts for the invisibility?” he queried.

The bustle of arriving and unpacking, and the battle with the shadow-dragon, had kept them busy. But now the thought loomed—why should this isolated valley bear only invisible life-forms? It was unheard of in the annals of science.

Dr. Damon’s tone became academic.

“I’ve learned a little, and surmised a lot, in the six months I’ve been here. It traces down to a certain type of grass, which has the property of invisibility. The herbivorous creatures eat the grass—rabbits, deer, etc. The carnivores—bear, fox, weasel, lynx—eat them. Excrement and decaying bodies go back to the soil—and back to the vegetation, including trees, bushes, moss. It’s a closed cycle, mutually kept up, as it would be in any isolated valley.”

“But what causes the invisibility itself?” It was Harlan who asked, leaning forward.

Dr. Damon’s tone became vague, dreamy.

“Perhaps it goes back a long way, in evolution. Evolution tries anything and everything. What does vegetation—to personify it—fear most? Being eaten. And being seen! If it were invisible, it might escape the crunching jaws of plant-eaters.

“Thus ages ago evolution may have tried this offshoot species, protected by invisibility. It failed, because of the animal sense of smell. It vanished in evolution, as so many abortive life-forms have. Only here in this valley it survived, and stayed to the present day.”

He waved a hand. “Sheer speculation, I admit. But however it happened, the invisible vegetation is here, and the resulting invisible animal life.”

“But what is the exact agent of invisibility?” Harlan insisted.

Crane didn’t like the tenseness in the chemist’s voice, nor the eager way he waited for an answer.

“That’s what I want to find out,” Dr. Damon returned. “And where you come in. Between us, we may be able to find out. I suspect it’s a hormone, a gland-product. Transparent life-forms are not unknown, of course—jellyfish, many worms, tropical fish, etc.

“A jellyfish is practically invisible in water. Thus it is hidden from its enemies. Its protoplasm is no different from ours, but contains gland-products that render it highly transparent.

“The same thing, to a much more marvelous degree, has occurred with this valley’s life-forms. Their protoplasm is just as material as ours, but almost completely transparent to light.” Crane nodded. “Clear enough,” he punned.

“But the dragons!” he asked in the next breath. “Why should there be invisible beasts never heard of before?”

“Not dragons—dinosaurs,” smiled the biologist. “A species of them closely related to the extinct Tyrannosaurus Rex, fiercest of them all. The dinosaurs died out, millions of years ago, in competition with rising mammalian life. But this invisible species had just enough edge to survive, though it has narrowed down to this lone valley.”

Dr. Damon’s voice lowered almost in awe.

“What we’ve stumbled on, in this protected valley, is the last vestige of one of nature’s great experiments—invisibility. It’s like finding live saber-toothed tigers, or mastodons, or submen.”

They all felt it—an air of having been projected into a strange and ancient vault of Earth’s long past. Empires of life had risen and fallen, like empires of man. Perhaps the Unseen Life had once lorded it over Earth, only to give way before keener-nosed, sharper-eyed species.

It was a chapter of evolution that had been totally unsuspected. The dead forms of the Unseen had all fossilized into opaque stone, leaving no slightest clue to their one-time invisibility in life.

Harlan broke the silence.

“You think, then, that you and I may be able to isolate this invisibility hormone?”

“Not here,” Dr. Damon demurred. “It would take years of work, in a well-equipped laboratory. The best we can do is collect samples of blood from these creatures and bring them back to civilization for that laborious research. The blood will contain the hormone. That’s our job, Harlan.”

The scientist rose. “Let’s get a good night’s sleep. Tomorrow we’re going out hunting—for invisible game!”

“You kill?”

Crane started. It was a surprise to hear the taciturn Pierre speak up of his own volition. The French-Canadian’s expression was again strange—almost protesting.

“Yes, why not, Pierre?” Dr. Damon said, surprised.

“Hard job,” Pierre grunted, turning away.

But Crane felt he hadn’t said what he meant. What went on in the guide’s secretive mind? And secondly, why was Harlan so keen on the invisibility angle itself?

When he went to bed, Crane asked himself another startling question. He had counted the grenades. There were four cases, containing six each, according to the bill of lading.

Two were missing!

Who had flung the second grenade?

CHAPTER V

The Man in the Mists

The hunt the next day proved a strange one.

“I know something of the layout,” Dr. Damon asserted. “Pierre and I explored the valley quite a bit. I even made a map.”

He displayed it before they started. The valley was roughly five miles long and a mile wide. It was densely wooded in the center, but more thinly at the ends where sunlight was often excluded. The invisible vegetation needed life-giving rays the same as any normal growths, absorbing nourishment through a colorless form of chlorophyll in their transparent leaves.

“Deer browse and sleep in the central section,” the biologist resumed. “We’re after them.”

“Where do the dragons hang out?” Crane wanted to know more practically. “Anywhere,” Dr. Damon said briefly. “I’m going along,” Jondra declared firmly. “I won’t stay at camp and bite my nails.”

The scientist shrugged, without an argument. “Well, we have the grenades,” he said.

“I’m going along too,” Crane stated.

“But the plane—”

“Will keep,” Crane finished shortly. “Besides, I’m a good shot.”

The scientist seemed pleased. “We can use another man with a rifle. Let’s go.”

Pierre leading, they trekked single file toward the center of the valley, brushing past unseen vegetation.

Crane looked around. Sheer, steep cliffs on all sides. They had kept the outside world out, and the things within from escaping. But the average temperature, it occurred to Crane suddenly, was hardly Arctic. In two days, none of them had been forced to wear more than mackinaw jackets.

“There are steam springs in the central area,” Dr. Damon explained. “This valley was formed, ages ago, by the sinking of land into a volcanic bed. The underlying heat works up through the soil, keeping the valley warm.

“No seeds flying up out of the valley can take root in the cold, snow-covered regions above. Thus the invisible vegetation has been confined.”

They saw the steam springs soon after, puffs of vapor rising from porous ground and curling vagrantly into the air. Often the ghostly shapes of trees and flowers would be outlined for a moment, revealing the verdant character of the invisible forest before them.

Singularly, here and there an ordinary pine stood plainly in view, green and solid.

“Some seeds drift down into the valley from above and take root. Seeds of the common visible variety.”

Crane suddenly chuckled. “Hunting invisible deer! Most hunters have a devil of a job bagging one they can see!”

“You think we’re fools to try?” countered Dr. Damon imperturbably. “Wait and see—”

He broke off and held up a warning hand. The line stopped. The scientist pointed ahead.

Two hundred yards beyond, a steam spring’s vapor wound lazily around and around a clump of bushes. Off and on, like the shutter of a blinking light, it outlined the form of a deer lying hidden. Sensing human presence and the consequent danger, the creature was on its haunches, ready to leap away.

But it was still there—a perfect target. The steam silhouette betrayed it, robbing it of the advantage of invisibility.

Pierre was slowly bringing up his rifle, with the caution of an experienced hunter. The others held their breaths. The gun steadied, then barked, sending echoes crashing back and forth between the cliffs.

Crane saw that Pierre had missed. The deer had leaped away at the crack of the gun, with all the lithe grace of its kind. It vanished utterly, passing beyond the steam curtain like a fading dream.

“What’s the matter with you, Pierre?” Dr. Damon snapped irritably. “First time I knew you to miss a perfect shot like that.”

The French-Canadian stood dazed, looking at his rifle in stark disbelief.

“Something push barrel,” he mumbled. “Spoil shot.”

“If that’s the best excuse you can think of—” The scientist glared at the man, then waved the party on. “Well, we’ll try our original scheme. We won’t find any more deer lying that conveniently in view.”

He explained his plan. “You’ve said frankly you’re a poor shot, Harlan. So you be our beater. Make a circle near the cliff edge quietly, and then cut straight toward us. Any deer you scare up will run our way.

“Now, there are three main springs ahead. Pierre, the one at the left. Crane, the middle one. I’ll take the right one. Between the three of us, we eventually should bag a steam-silhouetted deer.” The scheme was carried out. Harlan, carefully picking his way through the invisible forest, made a wide circle, then stamped noisily toward the three men with ready rifles. Two deer were seen leaping through the steam curtains—but away instead of toward them. Disconcerted, Crane’s shot went wild. Pierre and Dr. Damon hadn’t even tried to fire.

“Deer gone here now,” the scientist muttered. “We’ll try again in an hour.” The results were the same. The deer were again leaping away from them, at an angle they were unprepared for. No one fired.

“What’s wrong?” Dr. Damon rasped, his temper short. “You must make too much noise circling, Harlan.”

“I don’t!” the chemist snapped back. “If you ask me, something else scares them first, before I get near—and from the other direction.”

“A dragon?” Jondra gasped in alarm. “Of course not,” her father snorted. “We’d easily hear him.”

An hour later, Harlan tried again.

Three deer came leaping. At the instant Crane saw a silhouette over his steam spring, he tensed to swing his rifle from right to left. The deer’s motion the other way—from left to right—completely disconcerted him. There was no use to shoot blindly, a second later, at the portion of thin air into which the deer had dissolved.

“Damn!” he grunted. “We’ll never get them that way. They just don’t come from the right direction. What’s doing it?”

Harlan came back with a sober, almost frightened face.

“I think I saw—” he gulped.

“A dragon?” Jondra asked again.

“—the shape of a man!” Harlan finished.

His four listeners gasped. The thought of an invisible man, more than even the frightful dragons, sent chills down their spines.

“I saw it way ahead, running through the steam curtain, swinging its arms and chasing the deer away before I could get near. He must have made enough noise to scare the deer, though they couldn’t see him.”

“Nonsense!” Dr. Damon had recovered and almost yelled the word. “You’re all letting your nerves go. Pierre and I have been here six months without running across this mythical invisible man. It was a bear walking upright, naturally.

“Now scare up the deer again, Harlan. And don’t picture your grandmother in the mists next!”

Crane this time deliberately watched for the deer to be scared up from some point opposite Harlan. When a steam silhouette did appear, he had the exact bead. The crash of his gun hurled from the nearest cliff.

In his eagerness, arriving first at the spot, he yelped as an invisible hoof cracked him smartly on the shin. He stared down. On the grass before him lay a creature kicking in its dying reflexes. He could actually see only one thing—the mushroomed bullet hanging apparently in mid-air, lodged in an invisible heart.

Then he saw more. A pool of liquid was slowly outlined at his feet and began to tinge with a faint ruddy hue.

“Quick, Jondra!” Dr. Damon panted, running up. “The incisor and pump.”

Jondra opened the case she had carried all morning, handing over the instruments. With the skill and speed of experience, the biologist inserted a large hypodermic in an invisible jugular vein. Crane and Harlan sat on invisible animal legs that were still striking out. Dr. Damon attached rubber tubing and pumped transparent blood into a series of flasks.

“Haemolin—sodium citrate!” he barked at Harlan.

Harlan dumped the prepared solutions in the flasks, reagents that prevented coagulation and deterioration. It was all done in a minute.

The blood-drained body beneath Crane shuddered, gave a final heave, and was still.

“Watch!” Dr. Damon commanded.

Slowly the corpse took form. Inner organs misted into being, rapidly solidifying to visibility. Then overlying tissue precipitated out of thin air. Muscles sprang into being. A vast network of veins and arteries snaked into vision. Finally hide, hair and hooves appeared.

In the space of fifteen minutes, an ordinary deer lay before them, no different from its cousins in the outer world. With the passing of life and the breakdown of the delicate invisibility hormone, flesh hidden from human eyes had dropped into the visible spectrum.

It was uncanny, eerie, like a magician’s trick perfected to an impossible degree.

“But its blood is still invisible!” Dr. Damon crowed, holding one flask up.

To all appearances the flask was empty, clean. Even the refractive index of the solutions added had been largely erased.

“The secret of invisibility—in a flask!” Harlan murmured.

Crane glanced at him sharply. The man’s eyes were enigmatic.

Jondra shuddered and turned away from the scene.

“Let’s go back to camp—”

“What? Without taking along delicious cuts of venison?” her father scoffed.

Pierre already had his knife out and was expertly skinning the carcass. Soon after he was carving off choice steaks. The strong, salty smell of fresh meat rose into the air.

Crane fidgeted. “Isn’t this rather risky, in case one of the dragons—”

As if at a signal, a blasting roar thundered against the confining cliffs. A dragon had crept close, attracted by the smell, its noises camouflaged by the steady hiss of the surrounding steam spring. A treetop cracked, no more than a hundred feet away. In seconds the monster would be upon them, clawing and rending.

The five froze into the paralysis of fear.

Crane broke from it with a groan and fumbled for the grenade slung on his belt. Dr. Damon and Harlan were too stupefied to even remember them, or bring up their rifles.

Crane pulled at the pin with fingers of rubber. Before he could draw it, a hand clutched his wrist in a grip of steel.

“Pierre, you fool!” Crane snarled. “Let me go—”

“No kill beast!” Pierre muttered.

They struggled. The sound of monsters feet pounding heavily against their ears. Only seconds were left…

The grenade’s roar drowned out the triumphant bellow of the behemoth about to overtake them. A frightful scream shattered the air, as of a creature mortally wounded. Violent threshing sounded, as a mighty body writhed in death agony. A tree crackled and toppled, brushing at the five humans now stumbling away.

They stopped and faced one another, a hundred feet from the danger spot, pale, trembling, shaken to the roots of their souls at the narrow escape.

Dr. Damon suddenly let out a jubilant shout.

“It’s dying right on the spot! More blood! Come on, all of you, back to camp for more bottles—”

Not till an hour later, after they had returned, did the reptilian monster give its final gusty sigh of death. One last swish of an invisible tail flung dirt, needles and splintered branches in all directions. Then all was quiet.

The scientist brought up with a jerk as Crane held him from running close.

“Let go!” Dr. Damon screeched. “I have to pump that blood out before it’s too late.”

“You’ll wait five minutes, till we’re sure he hasn’t one last kick in him,” Crane said firmly, holding the biologist tight. “That tail, if I know anything about dinosaurs, could bash in the side of a locomotive.”

Jondra touched his hand and flashed him a smile of thanks.

But the monster lay still, and in fifteen minutes they had drained gallons of viscid fluid into the jars they had lugged from camp. Harlan dumped in wholesale quantities of his preserving chemicals.

Then they watched, gasping, as the corpse passed, by degrees, into the optical realm. Thirty feet long, from snout to tail-tip, spined, armor-plated, huge as a house, it lay in a mass of trampled vegetation and half-splintered trees which more slowly assumed a visible status in death.

It was the first dinosaur seen by human or near-human eyes for an unthinkable age.

“Look what it took to kill it!” Harlan said, awed.

The exploding grenade had torn out its entire chest. Bullets alone would have been a laughable farce against the gargantuan creature.

“Thank heaven for the grenades!” Dr. Damon breathed. “I’m wondering now how Pierre and I dared to sneak around for six months with our pea-shooters, under their very noses!”

He turned with a glowing face, waving at the bottles filled with invisible blood.

“We owe you our lives, as well as this, Crane. You tossed that grenade just in time!”

Crane said nothing. Obviously the others, paralyzed in blind terror, hadn’t seen that desperate moment when he struggled with Pierre. He looked at Pierre, but the impassive face avoided his. Pierre had no explanation for his astounding act.

But what bothered Crane the most was something else.

He hadn’t thrown the grenade! Nor had Pierre or the others! An unseen hand had done it.

Had there been a man’s shape in the steam mists?

CHAPTER VI

The Invisible Robin Hood

The following day dawned clear and bright. But there was a cloud in Crane’s mind. He watched Dr. Damon and Harlan busily transferring the blood to sealed cans, at the workbench.

Jondra watched moodily. This was not the right environment for her. Her feminine nerves would give way in a few more days.

Pierre sat in the sun, staring out over the valley, as though observing the shadow-life.

Crane’s churning mind strove to put the jigsaw puzzle together. Why had Pierre wanted the dragon to live? And what lay veiled in Harlan’s cold eyes?

And was there a fifth man—invisible—in the valley?

Crane strode to his plane, in sudden alarm. This was their only way of getting out of the valley—as a group. If someone had other plans.

Too late! He knew it the moment he entered the cabin. The panel-board lay smashed by a wrench from the tool chest. The drive-wheel had been battered to bits, and the steering post bent and twisted out of shape. The plane was useless, beyond repair!

They were trapped, in the valley of invisibility!

Crane stood cursing. It had been done the night before. Harlan or Pierre? Or—a chill went down his spine—the unknown presence?

Returning on the trail to camp, Crane held his rifle grimly. Harlan, Pierre or the invisible man? It surged through his mind like the beat of a drum.

Pierre still sat impassively before the cave entrance. His beady eyes did not turn. Crane watched him for a long, cautious moment. Was he shamming, fully aware that Crane must know of the ruined instrument board? Was he waiting for Crane to make the first hostile move…

“I’d advise you to drop your gun!”

Crane whirled. It was Harlan in the doorway, half smiling. An automatic in his hand pointed straight for Crane’s heart.

Caught off guard, Crane had little choice. He dropped his rifle. Pierre, starting from his daze, was tensing preparatory to lunging for his rifle, a yard away.

“Easy, Pierre!” Harlan warned, and the French-Canadian relaxed. “Now step to the right, both of you, away from your guns.”

As they complied, Dr. Damon and Jondra came running out.

“What is this, Harlan?” the scientist demanded testily. “What—”

He gasped, seeing the gun.

Harlan herded them all together, unarmed and helpless before his automatic. He looked from one to the other with undisguised triumph.

“So it was you, Harlan!” Crane said. “You smashed the instrument panel so we couldn’t leave the valley. What’s your game?”

“I can say it in one word—invisibility!” Harlan retorted.

“You mean you want the secret of invisibility for yourself?” Dr. Damon guessed belatedly. “Why? For what earthly purpose? Harlan, this is outrageous—”

“Shut up!” Harlan grinned strangely. “For what purpose? Can’t you guess? You mumbled about it all morning. That a person could take a dose of that animal blood with its invisibility hormone—and become invisible himself!”

Crane cursed, but at himself. Why hadn’t he seen that before? The secret of invisibility was of incalculable significance. From the first, Harlan must have plotted to hog it.

Harlan resumed. “Last night, Crane, after smashing the panel-board, I used your batteries. They furnished power for a little private radio in my belt. I sent a prearranged signal, to friends of mine. They should arrive, by plane, in an hour or so. You called my hand, but a little too late.

“We’ll take all those cans of blood. And then we’ll leave the valley—alone!”

The plain, brutal threat sent icy rage through Hugh Crane. His muscles knotted, and a growl rasped from his throat.

“Watch yourself, Crane!” Harlan yarned. “I prefer to let my less squeamish friends do the job. But if I have to, I’ll fill you full of lead! This is too big a thing to stop at anything. No one will ever find the four bodies rotting away in an undiscovered valley on the Arctic Circle.”

Crane leaped away. It was a desperate gamble, but Pierre might have a chance to get at Harlan afterward. Better the try than tamely to wait for certain death later.

Crane’s big body lunged forward like a football tackier, toes digging in the dirt. Head low, he aimed for Harlan’s legs.

Jondra screamed. Crane knew he could never make it. The ugly snout of the automatic leveled straight for him. Harlan’s finger began to squeeze. Crane mentally winced, waiting for the slugs that would churn through his brain.

A shot rang out…

Harlan had missed! Another shot…four more shots…and still no bullet touched Crane!

It was an impossible miracle. And then Crane gasped. He stopped short, staring at the amazing phenomenon occurring before him.

Harlan stood in a strangely unnatural position. His right arm was stiff before him, the wrist bent, the automatic pointed upward where he had pumped the useless shots. It was exactly as though a man had grasped Harlan’s wrist from the side, jerked his arm up, and twisted the wrist!

Yet there was no man there.

Harlan gave a shriek suddenly, as his wrist almost turned in a complete circle. His arm looped awkwardly back and he staggered in an off-balance position. A moment later the automatic dropped to the dust from Harlan’s nerveless fingers.

The automatic bounced once, then miraculously rose into the air by Itself, pointing at Harlan. The chemist reeled back, groaning with the pain of his bruised wrist, and at the unnerving sight of his own gun, unsupported, threatening him.

“It’s an invisible man!” Jondra whispered.

Crane tensed himself again. Friend or enemy? Had they been rescued from Harlan only to face a new menace?

“Who are you?” he demanded.

A low, quiet voice issued weirdly from a spot just above the gun, held by an invisible hand.

“I’m known as the Invisible Robin Hood.”

Crane’s mouth fell open.

“The Invisible Robin Hood? You mean that publicity myth that stirred up the country last year?”

“Publicity myth?” The unseen man chuckled. “Yes, I suppose most of you hard-headed people never did quite believe I actually existed as an invisible man. For a year I spied and tracked down criminal rings, and still no one believes I exist. No one except the criminals whose careers I ended, and my one confidant and contact man. Well—”

Crane could almost see the invisible shrug. Then he gasped, as his thoughts pierced back and back, through haze of mystery.

“You were with us all the time!” he exclaimed. “The take-off at Chicago—the plane was overloaded because of your added weight. During the flight, you once kept Jondra from falling. It was your hand on my shoulder that first indicated the valley to me, from the air.

“You kept me from striking Harlan, when he criticized my landing. You turned off the ignition key, to prevent danger of fire!” Crane gulped for breath. It was all so clear now! He could see dawning looks of understanding on the others’ faces.

“Yes,” came from the Invisible Robin Hood, “and I also threw the second grenade, when the dragon attacked you and Jondra. I was the one sneaking around the plane, when Jondra appeared, after the radio was smashed.

“Yesterday, I threw the grenade when you and Pierre struggled together, killing the second dragon.”

“You saved our lives?” Dr. Damon murmured. “Then you’re our friend—”

“Is he?” Crane’s face was suddenly grim. “It must have been you that spoiled Pierre’s first shot, and later chased away the deer, Mr. Invisible Robin Hood. And you also smashed the plane’s radio! You, as much as Harlan, have wanted to keep us locked in this valley without outside communication. Why?”

The unseen man seemed to ponder for a moment, silently. Then his disembodied voice, ignoring the accusations, addressed the dazed, crestfallen Harlan.

“I’ve tracked you from the start, Paul Harlan. I knew you would reveal yourself—Agent R-616!”

Harlan started. “You mean you know—”

The Invisible Robin Hood made an affirmative sound.

“Everything.” He addressed the others. “This man is a quisling—a member of the fifth column operating in North America!”

“Fifth column!” Dr. Damon gasped. “What do they want up here in this godforsaken—”

“Your invisibility, of course,” the answer came back sharply. “They got on the track of it when Pierre, delivering your first message, took time out for a few drinks. He slipped, mentioning the valley of invisibility. No one paid any attention except a fifth column spy. They’re all over, with their ears and eyes open for everything.

“Their headquarters was informed, in Chicago, and a certain masked Commander “Z” met a certain agent R-616 in a cheap hotel room, to give him his instructions. When Jondra put an ad in the paper for a chemist, Agent R-616 answered. Paul Harlan is an expert chemist, in real life. But he is also a fifth columnist—working for them, not you!”

“Good Lord!” Dr. Damon shook his head dazedly. “I never dreamed—”

“How do you know all that, Invisible Robin Hood?” Crane asked.

They could sense his peculiar smile.

“I am silent as the wind, swift as the tiger. I am unseen, undetectable. I see all, know all, hear all. At any moment I may be at your elbow, any where!”

He chuckled. “At least, that was my publicity, during my campaign against crime, for the benefit of those who needed to fear me. As a matter of fact, I stumbled on this accidentally.

“Since the European war, I’ve been investigating fifth column activities, the greatest menace on this continent today. For a year I was on the trail. It wasn’t an easy job.

“The fifth column has spawned and spread almost unhindered, like a malignant cancer. They are very clever, no quisling knowing more than one other quisling by name. The vast anonymous network has but one common basis—the undermining of the North American peoples. They envision the day when in one stunning upheaval, America the unconquerable will be fast in their grip.

“They have gained recruits—renegades to their country—from every walk of life, and by any and all means. Particularly they appeal to ambition and dissatisfaction.

“Paul Harlan is a typical example. He is ambitious. The fifth column converts have more ambition per square head than any other group in the country. And the fifth column G.H.Q. lavishes promises faster than any blitzkrieg ever took objectives.

“That’s what I’m up against—for I’ve vowed to smash the fifth column. The only way will be to reach the top men. I had laboriously tracked my way as high as Commander Z. But when he gave R-616 his instructions to get the secret of invisibility, I had to follow that branch trail.

“I was at Paul Harlan’s elbow when he met Commander Z. I was at Paul Harlan’s elbow when he stepped into the plane at the airport.”

Crane had to laugh at Harlan’s crushed air.

“You didn’t have a chance at all, Harlan, in your double-crossing—”

He broke off, lifting his head. They all heard it—a faint drone from the sky. A tiny plane sparkling high in the air, in the south. It rapidly enlarged into a two-motored cabin ship. It swooped, circling the valley.

“Harlan’s fifth columnist friends!” Crane whirled to the scientist. “What’s the way out of the valley by foot, that you and Pierre found? The sooner we leave, the better. We can pack enough food along to reach some town—”

Harlan was grinning. “The one trail out of the valley,” he put in, “is at the other end. I saw it on Dr. Damon’s map. There is also a clearing there, wide enough for a plane landing. I told my men to come down there!”

“We’re cut off!” the scientist groaned. “There’s no other way out!” They watched helplessly as the plane zoomed down, landing five miles away in the clearing at that end of the valley.

“They’ll be here soon, probably with sub-machine guns,” Crane muttered. “Their job is to mow us down.”

He automatically patted Jondra’s shoulder as she crept into his arms. They all knew without saying that the fifth column revolutionists were more brutal in their methods than any in history. There was no escape, and no quarter from which to expect help.

CHAPTER VII

The Fifth Column

The Invisible Robin Hood’s voice rang out.

“It isn’t over yet. We have guns. Stand them off. Lock Harlan up in the cave.”

His authoritative voice broke up the indecision of the others. They accepted his leadership instantly. Somehow, invisible though he was, there was an air of confidence and resourcefulness about him.

Crane and Pierre shoved Harlan into the cave, after removing all guns, ammunition and grenades. The solid pine door was swung shut and barred from outside. Harlan would have no chance to aid his fellow quislings.

Then Crane, Dr. Damon and Pierre distributed themselves at separate points just behind the outjutting logs of the crude walls. They would not be easy targets in the shadow of the rock overhang. Jondra stood beside Crane, a rifle gripped in her hands with grim determination. Crane squeezed her shoulder.

“Be brave, Jondra,” he whispered. “The Invisible Robin Hood will have a trick or two up his sleeve, if the stories about him are at all true.”

But for the present, he had simply done as they had—taken a strategic position. A rifle hung eerily at shoulder height, waiting for the adversary.

The enemy appeared within two hours, picking their way gingerly through the invisible forest. Harlan had evidently given them enough details of the valley and its strange unseen life to allow them planned action. They came directly toward the cave.

Crane’s heart sank. Six of them, hard-looking men, trained by the fifth column for just this sort of bloody work. Each carried a rifle, a knapsack of grenades, and three of them carried the parts of a portable automatic gun. They wore metal helmets and dull-gray uniforms. They were as efficiently prepared for their mission as any spearhead unit of a mechanized army in the European war.

The fifth column did nothing by halves, in their subversive program to undermine the thus far adamant American hemisphere.

The party stopped five hundred yards away, out of range of any but superb marksmanship. One man raised a speaking tube to his mouth and yelled across.

“You have Paul Harlan prisoner?” Sensing the Invisible Robin Hood did not wish to reveal his presence, Crane cupped his lips and shouted back the affirmative.

“Give yourselves up!” came back. “You have no chance against us. If you surrender quietly, we promise you safe passage back. We do not want your lives, only the secret of invisibility!”

“A lie, of course,” the Invisible Robin Hood’s whisper came. “The fifth column doesn’t know what the word ‘honor’ is. If we surrender, we’ll be shot down like dogs!”

Crane’s voice was an enraged taunt. “Come and get us!”

The leader waved a hand instantly, as though knowing that would be the answer. The men scattered in a semicircle and began creeping within gun range. Rifles barked. Shots tore around them viciously.

Crane shot six times, taking careful beads, and then cursed lividly. Not one of those clearly exposed men had dropped or even faltered.

“The invisible forest protects them,” Jondra said. “They’re running from invisible tree to invisible tree.”

Crane ground his teeth at the irony. Imponderable light went through the trees, but not bullets. The raiders had a perfect protective medium. They crept closer steadily, firing slowly, waiting to get within effective range.

Their tactics were mercilessly efficient. At three hundred yards, three men scurried together, and began hastily assembling their machine gun. The other three poured a withering rifle barrage toward the cave, to disconcert the defenders’ aim.

The gun was set up in seconds. Two men dashed away and the third threw himself full length behind the gun. In a moment its raking fire began systematically to cover every inch of the defended area.

Flinging Jondra flat on the ground behind the log wall, Crane himself shrank back. Solid sheets of lead were prying into every nook and corner. Splinters of wood flew viciously.

“What can we do?” came Dr. Damon’s wail from the other side. “We can’t fire a shot back!”

Crane knew there was one thing to try. Waiting till the swinging muzzle had arced away from him, he desperately ran out, hurling a grenade. It fell far short, digging a uselesss pit. The horrible chatter of the automatic weapon went on unabated, filling the valley with a rattling thunder.

As though his grenade had been the signal, the other five invaders ran forward boldly, grenades in their hands. In a few seconds, within range, they would bomb down the log walls.

“We’ve got to do something, Invisible Robin Hood!” Crane shouted. “For God’s sake, think of something! We’ll be murdered where we stand—” Crane suddenly realized he was talking to himself. The spot where the invisible man had stood seemed no different except for one thing—there was no rifle hanging mysteriously without support.

“Damn him!” Crane raged. “He’s deserted us! I knew I shouldn’t have trusted him—”

His voice was drowned out by a furious roar. The grenades! Then already the enemy were within range!

Crane waited for the log walls to crash around their ears, leaving them defenseless.

Instead, the roar was followed by the familiar crackling of a splintered tree. Then a ground-shaking thump, as its invisible bulk smashed down and measured its length on the ground.

Another roar. Again a tree gave its death wail and sought its grave.

Roar!—Crash!

Roar!—Crash!

Crane looked out. The five advancing attackers had halted in their tracks, grenades unthrown. They looked about, frightened, as the invisible forest seemed to have gone mad, threatening to crush them with hundred-foot falling juggernauts.

Hugh Crane let out a whoop of joy. The enemy couldn’t know that an invisible man was among them, tossing grenades at trees and bringing them down. It was as though a giant were uprooting them as clubs and beating the ground to blindly obliterate the invaders.

So it must have seemed to the thoroughly astounded fifth columnists. They fled back, like scared rabbits. They had been ready for anything, but not trees falling like leaves.

The man at the machine gun courageously stuck to his post, until invisible branches of a crashing tree knocked his weapon twenty feet through the air, and himself into a thicket of invisible brambles.

They retreated, but not in panic. Well trained, even in the face of a staggering surprise, they unhitched the machine gun and left at a dog-trot. One man ran smack into an invisible tree, knocking himself out. Two others put their arms under his shoulders and dragged him along. One man covered the rear at a slower pace, glancing back as often as he could, rifle ready.

Crane restrained himself from ordering a counter-attack. They were still a formidable force, in their well-organized retreat. Let them go. Crane contented himself with taking a careful bead, estimating the invisible trees by their winding path, and seeing one man jerk and clutch his arm. They would take back one wound, as well as their bruises from the falling trees.

“Well, how was that?”

Crane started. The Invisible Robin Hood’s voice had spoken beside his ear.

“Great!” Crane commended. “You saved the day! But why not follow them now? You could pick them off one by one—”

“No. If I tried that, they would radio to the plane. They are always in radio contact. The men at the plane—perhaps three or four men left on guard—would then know of an invisible man. They’d plan against me.

“I’ve seen enough of fifth column methods to know it’s a mistake to underestimate them. They’re not brainless, blundering gangsters. They’re intelligent, clever, efficient to the highest degree.”

His voice became low, thoughtful. “We have a tough fight ahead of us—to escape them. They’ll come back next with light field guns, perhaps, hurling shells from a mile or two back.”

“Good Lord!” shuddered Dr. Damon. “Just like the war in Europe—machines against men. We haven’t a ghost of a chance of holding out!”

A pair of invisible fingers snapped. “We have one good chance. Their whole mission is to bring back the secret of invisibility. Suppose we spill all the blood samples, and then let them know that Harlan will be killed by us.

“They might be willing to bargain for his life, since they would lose time starting at scratch again. One of the fifth column’s main creeds is speed, speed. Let’s talk to Harlan.”

“Spill the samples—no!” Dr. Daman almost shouted it. “I won’t allow it. I—”

Crane could feel the invisible man’s cold stare at the scientist.

“Have you thought of invisible fifth columnists, Dr. Damon? They would have a noose around America before we could say mechanized unit! They must not get that secret!”

Damon gasped. “Invisible fifth columnists!” He made no further objections.

Pierre swung open the barred door.

“Come out, Harlan,” Crane commanded. “We want to talk to you.”

There was no answer. Crane repeated his words, then stepped in impatiently.

“If I have to drag you out, like a stubborn child—”

His voice ground to a startled halt.

The interior of the cave-space was empty! The others crowded in, gaping. Harlan was simply not there, only his clothing piled in a heap.

“How could he have escaped?” Crane said dazedly. “Through solid log walls and a barred door?”

Jondra screamed. “That shadow at the door—”

They whirled. Something shadowy and vague was plunging through the doorway. It was in the shape of a man.

“Harlan!”

Crane leaped, but something shouldered him aside at the door. The Invisible Robin Hood had leaped first, and was chasing the escaping man.

Running outside, the rest saw only a translucent silhouette racing away into the forest, pursued by something they could not see at all.

Five minutes later the Invisible Robin Hood’s voice sounded before them, panting.

“Got away. Wasn’t quite invisible, but in the sunlight it was like keeping your eye on a flitting shadow. I lost him.”

“He injected some of the blood solution into his veins!” Dr. Damon cried. “I should have known he’d try it. The invisibility hormone is so powerful it works within an hour. He’ll be completely invisible soon, and stay that way till the dose wears off—probably twenty-four hours.”

“An invisible man against us!” Jondra whispered.

Crane looked at the Invisible Robin Hood—or the spot he occupied. “That complicates matters. Harlan, invisible, can come sneaking back and—”

He didn’t finish the sentence. It would sound too horrible to say it. But suddenly he did say it, in altered form.

“Why not sneak to their camp and murder them in their sleep?” he demanded. “Every minute that goes by endangers us. And all America! You’re invisible. They can’t touch you. Take a gun and shoot them down like they would have shot us down.

“I know it won’t be an easy thing to do. Any decent man’s soul revolts at being a cowardly assassin. But you’ve got to, Robin Hood. It’s the only way!”

The others looked at each other, shuddering. It was a stark, merciless suggestion. The height, perhaps, of sheer deliberate murder. But the stakes were equally in proportion.

There was silence from the Invisible Robin Hood for a long moment. Then a deep, grim sigh.

“Give me a rifle and twelve bullets,” he said.

A moment later he was gone, as unseen and silent as the wind.

CHAPTER VIII

Under Fire

Crane said little to Jondra as they waited, his arm across her shoulder. Dr. Damon seemed to find the ground interesting. Pierre stared out over the invisible forest, his black eyes enigmatic as always.

They strained their ears to hear shots. The shots that would announce human beings murdered without a chance, by an invisible assassin. It was a grim, soul-searing game that was being played out in a sunken valley, far north of the teeming cities of America.

Crane started. A twig had crackled, somewhere out at the fringe of the invisible forest. He jumped up. Their invisible friend was returning.

“Robin Hood? You—”

A shot rang out. The bullet whistled past Crane’s ear and thunked into the logs behind.

Jondra screamed. “Look there—a gun pointing at us!”

Two hundred feet ahead, a gun hung in the air.

“Harlan!” groaned Dr. Damon. “He’s invisible now and he’ll kill us!”

Another shot split the air, as they all leaped for the cave door. Harlan, a poor shot, had missed again. But if he pumped shots at their massed group, entering the doorway, he couldn’t fail to get one or two. Then he would stalk them inside, shoot them down one by one…

Even as he ducked and whirled, Crane saw what happened. Something wrenched the gun from Harlan’s hands. It swung around as a club. It whacked against an invisible tree, the stock shattering. For a moment it hung, then began moving toward them, at the pace of a man walking.

The battle of the invisible men had been short.

“Did you get him, Robin Hood?” Crane queried eagerly.

“No.” The bodiless voice was weary, defeated. “I tried to club him, but he slipped away. He’s completely invisible now. And that’s why I failed in everything…”

“Failed? You didn’t get the other men?”

Again a weary, “No.”

“Everything seemed perfect,” the voice went on. “The men were all outside the plane—ten of them altogether. Creeping close, I shot one.” He seemed to shudder a little.

“But when I aimed for the second, a shot rang back. Harlan had been expecting me. Guessing my position by the hang of the visible rifle, he could get me eventually, poor shot though he is. I couldn’t get him. He was behind the plane.

“There was only one thing to do. I had to drop my giveaway—the rifle—and leave. Still, I hung around a few minutes, debating some other plan. For instance, using a grenade, and blasting plane and all apart.

“Suddenly, it came to me like a blow. Harlan now knew I was there. Therefore he would run to this camp and murder you, not having me to fear. He could do his job much quicker than I could do mine, and still have time to return and rescue whatever men remained. That’s how the fifth columnists figure those things—in plain, cold, emotionless figures.

“I guess I came back just in time, running all the way. Harlan’s first shot told me where he was. I ran to him—and you know the rest.”

Crane pondered. “Invisible man against invisible man! No matter what you do, he can duplicate it. And Harlan has the advantage. He has more men and more arms. Good Lord, what can we do?”

It was not stalemate. It was certain victory for the enemy.

* * * *

Dusk came, as the sun slowly sank. Darkness settled over the valley of invisibility and terror. And menace.

“Suppose they attack at night?” Jondra breathed.

“I doubt it,” the Invisible Robin Hood said. “Darkness gives us more advantage than they, on the defensive. All blitzkrieg tactics take full advantage of the best, not the worst of conditions. However, we’ll take precautions. I’ll stand guard outside. Crane, you sleep at the door. The rest back in the cave.”

The night hours wore away. Crane awoke from the doze he had achieved, disturbed by some sound in the forest’s night quiet. The stealthy pad of feet! Closer they came, silently shrieking of threat.

Where was the Invisible Robin Hood? Why wasn’t he on the job? Had he left them exposed to throat-slitting by the invisible Harlan?

Quivering at the frightful thought, Crane raised his rifle. He felt blind and helpless, as so often before. How could he fight an unseen presence who could come from any side, strike at any unannounced moment?

Was a sharp knife even at that moment sweeping toward his unprotected back?

The next sound Crane heard was the most welcome in the world. It was a sniff. An animal sniff, followed by the low growl of an invisible bear, snooping around the camp for tidbits of food, most likely.

Crane fumbled for a piece of the deer meat and tossed it out.

“Here you are, old top,” he whispered. “I’m glad it’s you rather than a certain invisible snake. Hope all your children are visible. Now scram.”

A pleased grunt sounded, and the slice of meat floated off into the starlit night.

Crane didn’t doze any more. Dawn was breaking. A new day was here—the day that would tell the story, one way or another.

A hand gripped his shoulder.

“I’m back, Crane.”

“Robin Hood! Where were you? Damn you, man, do you realize you left us at the mercy of Harlan, if he had come?”

“I knew he wouldn’t,” the unseen man said calmly. “He was too busy guarding his own camp. Besides, it’s chilly at night. Don’t forget, he has to run around naked. His clothes are still visible.

“I went to their camp. I had grenades along. I thought of blowing the plane up, with them all inside. But only four were in. The rest were elsewhere, in some cliff cave I’d have to search for all night. If I did eliminate the four, Harlan would again have raced here and bombed this camp to smithereens. Any way I looked at it, they would come out ahead.”

His voice changed to bafflement.

“I’ve been thinking all night, hoping to figure out some other plan. We must try something soon, now that day is here—”

“For Pete’s sake!” Crane exclaimed, thumping his head with his knuckles. “What am I waiting for? If Harlan could become invisible, why can’t I? Two invisible men against one and we can get him!”

He was already ducking into the cave, striding for the work bench at the rear and its bottles and cans of invisible blood. He picked up a flask, apparently empty, but heavy with its unseen contents.

Pulling out the stopper, Crane filled a hypodermic lying nearby. Eagerly he brought the needle close to his left arm’s largest vein, for injection.

A hand knocked the hypodermic away, shattering it on the ground.

Dr. Damon had watched, rubbing his eyes, and then bounded from his bunk.

“You fool!” he barked. “That stuff is poison. I would have suggested it yesterday, except for that. Any animal blood is poison in a human being’s veins, except certain types of anthropoid blood. Harlan will be dead before this day is over!”

“Did he know that?” Crane gasped.

The scientist nodded.

“The fifth columnists are fanatics,” the Invisible Robin Hood remarked. “Harlan sacrificed his life for the cause.”

The words seemed to echo in the cave.

Crane picked up another hypodermic, grimly.

“Two invisible men against one, and we have a chance—”

Dr. Damon looked at him, but said nothing. The Invisible Robin Hood made no move to interfere. They would have to stand aside now, and watch deliberate suicide.

With a tightening of his lips, Crane prepared to plunge the needle home. Again it was knocked out of his hands.

“I can’t let you!” Jondra sobbed. “Isn’t there anything else we can do?”

She was facing the spot at which the Invisible Robin Hood stood, bitterly. “In smashing the fifth column, Mr. Robin Hood, you’re smashing us just as ruthlessly. You started all this—by not exposing Harlan at the beginning. You played the game your way, and we suffer as pawns. There’s probably no room for emotion—love, for instance—in your career of giant-killing. You’re just a cold, unfeeling human robot—”

The tirade ended in a choke, as the girl buried her head against Crane’s chest.

Love! That was a queer thing to bring up in this valley of hate and death and menace.

An aura of sudden sadness radiated from the unseen man. Crane could feel it. Hard he might be at times, striving for his goals at any cost, but beneath it he was human. And somewhere, something had seared his soul—but still left him human.

There was the merest murmur.

“Love? I loved a girl once. She is like you, fair, sweet…”

The voice trailed away. Then it spoke softly again.

“Wait here. I’ll investigate the enemy’s activity. If anything else can be done—”

He was gone.

* * * *

His voice was still soft when he returned, an hour later. Soft but grim.

“They’ve set up three field guns, about two miles back. Judging by their positions, and the stacks of ammunition beside them, they’re ready to bombard this entire end of the valley. Raze it flat!”

Broooommmm!

The dull thump sounded, followed a few seconds later by a ground-shaking roar. A quarter-mile to the left of them, where the shell landed, a shower of dirt sprayed into the air. With it, unseen, had gone a shredding of the valley’s shadow-life.

A second shell landed fifty feet nearer. A third still nearer, bringing down on them a fine stinging hail. The artillerists were finding the range rapidly.

“They’ll systematically sweep every inch of our end of the valley,” the Invisible Robin Hood said, still softly. “Everything will go—forest, cave, animals, dragons—”

“Dragons!” It was Pierre’s voice, in a deadly rage. “They kill dragon! Fear dragon! But I will kill them! I, Pierre, will lead my dragons—”

He lapsed into rapid French, shaking his fist in the direction of the thumping guns. The others watched in astonishment.

“Pierre!” Crane snapped. “Keep your head, now of all times. We need every man—”

He stopped, gasping. Pierre was stripping off his clothes. The garments dropped. The body exposed was translucent. Direct rays of the sun stabbed through and through, outlining the bones. And rapidly, even the skeleton was fading into the unseen background of air, as the hormone of invisibility bleached the guide beyond the color-spectrum faster than any dye had ever worked.

“Pierre!” Dr. Damon cried. “You took a dose of the blood. You’ll die!”

“Pierre does not die. Pierre will lead his dragons—”

With a wild shout, the wraithlike form stalked toward the forest.

“Mad! Utterly mad!” Dr. Damon whispered. “I suspected it all along, in the previous six months. The thought of the invisible dragons preyed on his mind.”

Crane jumped to catch Pierre, but an invisible hand stayed him.

“Let him go. Time’s short. We have to dodge these shells. We can’t run forward openly, for they’ll be waiting for us. But we can move along the cliff-edges, in comparative safety, ahead of the barrage.”

“Suppose we survive the bombardment, by a miracle?” Crane said hopelessly. “What then?”

“Pierre is leading the dragons!” the Invisible Robin Hood breathed.

Crane started. Had the Invisible Robin Hood gone mad too? But there was little time to speculate. An invisible hand, covered with fine wire mesh, grasped his, pulling him away.

Jondra had Crane’s other hand, and her father brought up the rear.

They were to play a new game—dodging shells.

CHAPTER IX

Blood Barrage

Crane was never quite clear how they escaped the holocaust of bombardment. With the precision of army artillery, the field guns methodically lobbed their shells back and forth across the narrow end of the valley. Starting at the cliff-face, the barrage worked inward.

The tenth shot struck the cave home, scattering logs in all directions. The four were driven forestward, to keep ahead of the destruction. Eventually, they would stumble into the arms of the enemy.

“What plan have you?” Crane yelled above the terrific rumble of sound banging between the cliffs. “Why didn’t you take the last chance—letting me become invisible? What chance is there now?”

But no answer came from the man whose unseen hand pulled them forward.

Crane noticed suddenly that they were working their way toward their own wrecked plane. Had the Invisible Robin Hood forgotten that it was useless for flight? Crane tried to jerk away. Why let this madman lead them to certain destruction?

“You fool, stay with me!” came back the fierce retort. “Now’s our chance!”

He was tugging them toward the plane. The barrage had swung toward the other cliff-face, temporarily. They were safe for a few minutes from flying steel splinters and crashing trees.

“Quick!” commanded the Invisible Robin Hood. “Run your gas out on the ground. But not the reserve tank. Start your engine and let it run on the reserve—at high speed.”

Crane complied, shaking his head in angry bewilderment.

The fuel poured out, soaking the plane and all the surrounding ground with its grass and bushes. The motor coughed, but started willingly enough, fed by the reserve tank. Crane set the throttle at half-speed, just at the point where the whole ship trembled and sought to move. A little more and it would trundle forward, to ram into trees with its controls wrecked.

“Now run!” the invisible man yelled. “Run as fast as you can—”

And he insanely led the way directly through the barrage line!

The raking shells began to pound nearer and nearer, like a returning pendulum. Trees crashed behind them, clutching at them with whipping branches. Flying splinters thudded viciously against invisible tree boles.

Crane felt a nudge in the flesh of his left arm, and the warm stickiness of blood, but raced on. He was half carrying Jondra. An invisible arm was pulling Dr. Damon along faster than his age could propel his muscles.

The universe seemed falling about their ears. But they made it.

The thumping barrage swung away on its ordered course. It neared, now, the spot where the plane lay.

Panting, they stopped and watched as a livid sheet of flame sprang from the spilled gasoline. Trails of fire promptly cracked into the air, following the branches of invisible trees. Billows of smoke swirled into the sky.

In seconds, the first tentative flames had become a roaring forest fire, fanned by the propeller blasts of air. The next shell sent the plane into oblivion.

And it scattered firebrands.

“It worked!” The Invisible Robin Hood’s shout was a cry of triumph.

The fire became a blazing inferno. Rapidly treetops touched off from one to the next. A line of flame strung itself across the valley from cliff to cliff. Then, like an enraged bull, it charged forward toward the center of the valley.

Demon fire had joined the battle in the valley of invisibility!

It was a strange sight. The flames seemed to spring out from nowhere, burning on invisible fuel. Branches and trees became visible, under the scorching death, but again vanished in the consuming blaze.

Crane hardly realized he had been screeching like a maniac for some time.

“I get it!” he yelled above the din. “Jondra! Dr. Damon! We’re safe here, where the barrage blew the forest to bits. No fuel for the fire. But the flames will sweep through all the rest of the valley. Harlan and his gang can’t blitzkrieg a fire away. They’re sunk!”

His voice changed just as suddenly. “But wait—suppose they simply turn the field guns and blast clear their end, before the fire comes. Then they’re saved too.” He groaned. “We’re still no better off!”

“Pierre is leading the dragons!” the Invisible Robin Hood said enigmatically. In more practical tones, he added, “The valley is narrow. The fire will drive all animals before it, toward the enemy’s camp. Including the dragons. Have you ever seen what a herd of elephants do on a stampede?”

Jondra shuddered. “The men will be trampled to death!”

Their jubilance over victory was subdued by the thought of what must be happening on the other side of that pitiless, searing, charging wall of flame.

The field guns stopped thumping abruptly. Crane could picture the gunners staring at the oncoming wave of fire in horror. Then screaming and running. No “strategic retreat” this time. Just a blind, panic-stricken flight.

No safety in their plane, with its gasoline but fuel to feed the enveloping flames. No time to take off. They could only stumble hopelessly on, to the very end of the valley. They would turn around then, with their backs to the cliff, eyes horror-struck at their doom. They would tear at each other in the attempt to struggle up the one scalable path out of the valley.

But before this would come the waves of fleeing animals. The animals would dash themselves against the cliffs, making them slippery with blood. The monstrous dragons would thunder up, snorting, bellowing, trampling. Their mighty feet, as they raced up and down seeking escape, would crush all the lesser animals. Including man.

It would be a sight no one would want to see.

The four were silent, waiting. In a short hour, the whole valley had gone up in smoke. Walls of smoke had mercifully screened from their eyes any glimpse of the happenings there. The steady crackle had camouflaged all sounds.

The flames died, then. The valley lay a smoldering ruin.

“Every living thing is wiped out!” Crane grunted. “This is the valley of death!”

“Not quite—listen!”

They heard the crackling of a ponderous body through the dying embers ahead. Through the pall came limping a smoke-silhouetted dragon. Crane gripped a grenade but then relaxed. The beast, staggering and groaning, had no interest in them. It sought a cool spot. Easing its bulk down in the unburned section, it licked its wounds.

“Some of the animals escaped,” the Invisible Robin Hood mused. “Perhaps the fleetest deer, and a few of the armor-plated dragons. Undoubtedly same of the vegetation here and there, in niches. The cycle could start again…”

His voice trailed away thoughtfully.

CHAPTER X

“The Secret Must Remain a Secret!”

They returned to what had been the cave home. Most of it was a gaping ruin, but the back portion was comparatively unscathed. Food supplies remained, and a dozen sealed cans of blood.

Dr. Damon picked them up eagerly. “I thought they would all be destroyed. I’ll take these back. I’ll still announce to the science world the great discovery of invisibility!”

His voice changed to a bark.

“Here—stop that!”

Unseen hands were stamping a rifle butt down on the cans, splitting them open. The invisible fluid vanished into the dirt. Dr. Damon attempted to wrench the rifle away. A hand that could not be seen roughly pushed him away.

Crane clutched at an arm whose position he guessed.

“Listen, Robin Hood! Just—”

A fist thudded against his chest, breaking his hold. He almost reeled back against the wall.

For a moment, loud breathing sounded from the invisible man, as though he were a jungle animal over a kill.

“Back!” he grated. “Stay back, or I’ll—”

Suddenly his voice changed, to its usual softness.

“I’m sorry. But I must do this. The secret of invisibility must remain in this valley!”

Crane’s thoughts clicked. The last bits of the puzzle slipped into place.

“I see!” he murmured. “That’s why you didn’t reveal yourself to us right away. You played a lone game. You smashed the radio, so the outside world could not be told of this.

“You chased the deer because you didn’t want Dr. Damon to get blood samples. You wanted neither the fifth column to get the secret, nor Dr. Damon. Nor anybody—except yourself! But what right have you, Robin Hood, to deny Dr. Damon, a scientist, his discovery?”

The Invisible Robin Hood’s voice came back in deadly earnest.

“No one must have the secret of invisibility—ever! I discovered it by accident, by a physical principle rather than through a hormone. I’ve not misused it. Many others would do good with it, as I have. But once it got into the wrong hands—chaos! The world would be a madhouse. Invisible deeds of crime! Invisible spies! Invisible armies! Think of those things.

“I know you’re an altruist, Dr. Damon. You probably think of good uses for invisibility—as in crushing crime. But you can’t quite know, as I do, what power it gives a person. You can’t quite know that you’re tampering with dynamite that can blast the world!

“I hope you see my viewpoint. That if it’s within my power to prevent anyone else from having my secret, I must do so!”

Jondra spoke up firmly. “It’s cold, ruthless reasoning. But it’s plain logic!”

The two men glared, still angered, but they made no move as the rifle butt resumed cracking open the cans, spilling the last of the blood samples into the ground.

“There!” It was a deep sigh from the unseen man. The sigh of one who has accomplished a vital mission.

An echoing sigh came from Dr. Damon. His shoulders sagged. He turned away without a word, brokenly.

Crane could think of no way of consoling a man who had just seen the discovery of a century trickling into oblivion. Nor could he think of any way of denying that the Invisible Robin Hood had done right.

He turned to Jondra. He had something to say to her, anyway.

* * * *

Dawn stretched its rosy fingers across a seared, blackened valley. The four people—one invisible—picked their way to the other end. The fifth columnists’ plane, in its clearing, had freakishly remained unburned, its fuel untouched. The saboteurs had not thought that miracle would happen, or they would have huddled in the ship.

Instead, they had fled. All that remained of them now was scattered somewhere in the black strewing of scorched bones littering the cliff-face. Crane shuddered, at thought of what terror had reigned here the day before.

“Look!”

Jondra’s hand pointed halfway up the cliff-face, along the steep path that led out of the valley. Pierre’s body hung there, against an outjutting stone—visible once again in death. Skin half black, the flames had just reached Pierre. One arm was stiffly outstretched, as if he had been beckoning. The expression on his face was strangely at peace.

The Invisible Robin Hood spoke solemnly.

“Have you guessed about Pierre? When he drank too much whiskey that time, delivering Dr. Damon’s letter, he babbled into the ears of a fifth column spy, as I mentioned. The spy took all the conversation down, in a report to Commander Z. I saw the verbatim wording.

“In one place, Pierre had said, in drunken French:

“I just dare the blitzkriegers of Europe to attack our shores! I will lead the invisible dragons out of the valley. They will frighten the enemy. They will stamp the enemy flat. Yes I, Pierre, will save my country from the enemy, for I will lead the invisible dragons against them!’”

The invisible man’s voice rose a note. “I salute you, Pierre! In your own way, you were ready to defend your country and continent against invasion, even if you were mad in the thought. And you did lead the dragons…”

* * * *

Crane was not surprised when the Invisible Robin Hood, a while later, made no move to enter the plane.

“I’m staying. Perhaps two or three of the dragons are alive yet. I must hunt them down. And any others of the Unseen Life. Then I must destroy every last vintage of the Unseen Vegetation, with burning gasoline.

“Leave with me, besides food, a rifle, ammunition, the grenades, and a tin of gasoline. Invisibility is a menace. When I leave, this valley will be barren of life. After that”—he paused—“there are many things to do.”

Jondra felt for his arm. “You said before that you loved a girl, and that she’s still alive. You’re wrong in denying yourself—and her—that love, no matter what tasks you set yourself!”

A low, almost harsh chuckle sounded. “Look!”

A switch snapped. With startling abruptness, Crane and Jondra saw a tall, lithe young man before them. He was completely sheathed in what looked like fine chain-mail. The gauntleted hands reached up to unfasten the helmet-like hood. Hugh Crane and Jondra Damon gasped in unison.

The face revealed was hideous beyond belief. Great burn-scars obliterated what had once been strong, handsome features. There was little of nose or hair. The lips and jaws were a network of white lines where surgical thread had sewed mangled flesh together. The mouth still looked like an unhealed wound. Only purple folds of lumpy scar tissue remained.

Jondra and Crane stared at this dreadful, once-handsome caricature of a man with horror-stricken eyes.

“I discovered my method of invisibility in a laboratory,” said the Invisible Robin Hood. “There was an explosion—”

“Oh, you poor fellow!” Jondra cried and burst into tears.

Again there was a click, and the Invisible Robin Hood vanished from their sight.

* * * *

They took off a little later in Crane’s airplane, which had been quickly but efficiently repaired. Three people were in that plane, leaving forever behind them a land which time had truly forgotten—Hugh Crane, Jondra Damon and her scientist father, bitter lines about his mouth in the knowledge that the greatest discovery of all time had come to naught.

Crane looked down. He could see nothing of an invisible man stalking invisible beasts. Somehow, it had all been a horrible dream. Not the least tragic had been that poignant moment when the Invisible Robin Hood had figuratively unmasked himself, a splendid young man whose caricature of a face would curse him through all his days.

Curse him, and deny him the fruits of a happy life. But raw courage and high achievement would be his, and Crane knew in his heart that when ugly menace stalked the highways of crime, the Invisible Robin Hood would somehow be on hand, ever on the alert against men who would use the marvels of science for their own vicious purposes…

Hugh Crane turned to Jondra. Thank heaven, she at least had come out of this all unscathed. And she was entirely visible. In fact, come to think of it, she was a most attractive-looking young lady.

Jondra, with a woman’s intuition, read the message in Crane’s gray eyes.

Her answering smile was the most visible thing Crane had ever seen.