American expatriate John Robie living in high style on the Riviera is a retired cat burglar. He must find out who a copy cat is to keep a new wave of jewel thefts from being pinned on him. High on list of prime victims is Jessie Stevens, in Europe to help daughter Frances find a suitable husband. Lloyds of London insurance agent is using a thief to catch a thief. Take an especially close look at scene where Robie gets Jessie s attention, dropping an expensive casino chip down decolletage of French roulette player.

Finally home after his astounding journey, Mortimer resumes his simple life until the day he receives a mysterious phone call. Famous artifacts from museums and private collections around the world are missing. The person claiming responsibility for the thefts goes by the moniker - the Crimson Thief, a ghost that the police can do nothing about