The Assassin's League
G. T. Fleming-Roberts
Published in the 10/1937 issue of Secret Agent X.
"A wealthy arms manufacturer and a powerful ganglord killed themselves, when they had the world by the tail ... Secret Agent X sought to discover the baffling, contradictory cause of their enigmatic suicides. But even the Agent's amazing disguises failed him. For a strange, beautiful girl was able to pierce every clever face worn by the man of a thousand faces."