We were introduced to Ferdinand Waldo Demara (Tony Curtis) as he was being arrested by the Coast Guard in New England and, in flashbacks, we find out his amazing tale. Demara quit school to join the Army, but failing to move ahead quickly enough, he faked credentials and became a Marine. When his charade was uncovered, he faked suicide and pretended to be a monk, but was caught again and thrown in jail. The prison's warden became friendly with Demara, which gave him the details to impersonate the warden when he was released from jail and land a jail job of his own. The very crafty Demara went on to pretend to be a doctor, dentist, teacher and member of the Royal Canadian Navy, but saved his best play for last. When the FBI assigned an agent to track him down, it seemed his impostor days were numbered -- until it was revealed that the agent was Demara himself!