When a prominent picture broker, a popular comedian, and a respected retired gentleman mysteriously vanish from Chicago without a single clue left behind, the police are left completely baffled. Sergeant Morley turns to the brilliant and unconventional amateur detective Jimmie Lavender for assistance in unraveling the baffling puzzle. Lavender's sharp intellect quickly discerns that these seemingly unrelated disappearances share a strange and intricate connection. As the investigation deepens, the sleuth focuses on a theatrical actress named Sidney Kane and an empty office that serves as a blind for something far more elaborate.
While Lavender's friend Gilly accompanies him through the bustling city streets and interviews concerned relatives like the lovely Miss Shirley Minor, the clues begin to point toward an astonishing truth. It slowly becomes clear that the missing men are actually the same person playing a complex game of dual identities. The investigation leads Lavender to a suburban home where he confronts the actress who has been shielding the runaway man. Ultimately, the mysteries of the deserted office, the missing comedian, and the vanished father resolve into a surprising domestic drama rather than a criminal plot. Through a series of astute deductions and a final confrontation, the true motives behind the elaborate masquerade are brought to light, restoring order and revealing a long-kept secret.