Discovering that a ventriloquist (Danny Kaye) is travelling to Zurich, a spy ring hides plans for a deadly secret weapon in his dummies' heads. When a second spy ring learns of the secret plans in his possession, they descend upon his hotelroom. The result is two dead agents, and Jerry is blamed. Hunted through London as the "Red-Headed Ripper", Jerry flees both police and spies. Eventually, the ringleader of the spies is apprehended by Jerry who is hailed a hero and is free to marry his beautiful lady psychiatrist Ilse Nordstrom (Mai Zetterling).
