I. The Mystery of the Spy
II. The Mexican Cabaret
III. The Secret Service
IV. The Gyroscope Aeroplane
V. The Archeologiest
VI. The Medical Party
VII. The Buried Treasure
VIII. The Curio-Shop
IX. The Gun-Runners
X. The Air-Terror
XI. The Radio-Detective
XII. The Triple Mirror
XIII. The Wireless Wire-Tapper
XIV. The Artificial Kidney
XV. The Arrow Poison
XVI. The Stolen Secret
