AllMovie

It took two directors to bring this modest British thriller to the screen. The story concerns a gang of international jewel thieves, headed by a "mystery man" who is never seen and who communicates with his minions through a microphone. Rival criminal Jacques LeClerq (Sebastian Shaw) gains the gang's confidence, joining them on their biggest caper. Only when it's too late to back out does LeClerq reveal that he's actually a member of the French police. Without revealing the identity of the criminal mastermind, it's worth noting that one of the actors plays a dual role, a fact spelled out in the opening credits.