The Man Who Knew Too Much

American tourists James Stewart and Doris Day are witness to the street killing of a Frenchman (Daniel Gelin) they've recently befriended. Before breathing his last, the murder victim whispers a secret to Stewart (the Cinemascope lens turns this standard closeup into a truly grotesque vignette). Stewart knows that a political assassination will occur during a concert at London's Albert Hall, but is unable to tell the police: his son has been kidnapped by foreign agents to insure Stewart's silence.