A British agent's son is kidnapped and held for a ransom of diamonds. The agent finds out that he can't even count on the people he thought were on his side to help him, so he decides to track down the kidnappers himself.

One Rolls-Royce belongs to three vastly different owners, starting with Lord Charles, who buys the car for his wife as an anniversary present. The next owner is Paolo Maltese, a mafioso who purchases the car during a trip to Italy and leaves it with his girlfriend while he returns to Chicago. Finally, the car is owned by American widow Gerda, who joins the Yugoslavian resistance against the invading Nazis.