Jack Martin is an American entertainer working cabarets on the French Riviera. An impersonation of philandering industrialist Henri Duran is so convincingly that even Duran's beautiful wife is fooled by it. When Duran's business interests compel him to be in London when he should be hosting a large soiree at his home, Martin is persuaded to impersonate Duran at the party. But matters threaten to get out of hand when Martin, dressed as Duran, is confronted...