A chance accident causes a nuclear physicist, who's selling top secret material to the Russians, to fall under FBI scrutiny and go on the run.

In this Americanization of the 1931 German thriller, both the police and the criminal underworld stalk a mysterious serial killer who preys on little girls.

Mark marries Marnie although she is a habitual thief and has serious psychological problems, and tries to help her confront and resolve them.