After Silvia Broome, an interpreter at United Nations headquarters, overhears plans of an assassination, an American Secret Service agent is sent to investigate.

In this drama, the popular French film star of the '30s and '40s Jean Marais plays Victor, a disgruntled, cranky old man who is forced to come to terms with the fact that he is now the guardian of his mulatto grandson Clem (Serge Ubrette). Victor is shocked to discover his grandson's mixed heritage when he travels to London to pick him up, but resigns himself to the situation. Once at home in France, the brash Clem manages to steal the heart of the most coveted young woman in town, but that only gets him into trouble with her tough-guy boyfriend and his buddies. Meanwhile, Grandpa is trying to come to grips with his own biases as best he can.