| Hamilton Cleek, The Man of the Forty Faces and once known to the Police as "The Vanishing Cracksman," now the great Detective in his various disguises as Monsieur Georges de Lesparre, Philip Barch, George Headland. |
| Superintendent Narkom, of Scotland Yard. |
| Lennard, his chauffeur. |
| Hammond } Detective Sergeants. |
| Petrie } |
| Mellish, Police Officer. |
| Dollops, Cleek's trusted assistant. |
| Lord St. Ulmer, the father of |
| Lady Katherine Fordham, who is in love with |
| Geoffrey Clavering, the only son and heir of |
| Sir Philip Clavering, of Clavering Close, and |
| Lady Clavering, his second wife. |
| Count Franz de Louvisan, found mysteriously murdered after having forced Lady Katherine to become engaged to him. |
| Ailsa Lorne, Lady Katherine's friend and companion. |
| General and |
| Mrs. Raynor, Lady Katherine's relatives. |
| Harry Raynor, their son. |
