Private eye Mike Hammer sets out to avenge the murder of a female client and falls foul of crooks intent on stealing a crate of radioactive isotopes. Robert Aldrich's crime thriller based the novel by Mickey Spillane, starring Ralph Meeker, Paul Stewart and Cloris Leachman.

One evening, Hammer gives a ride to Christina, an attractive hitchhiker on a lonely country road, who has escaped from the nearby lunatic asylum. Thugs waylay them and force his car to crash. When Hammer returns to semi-consciousness, he hears Christina being tortured until she dies. Hammer, both for vengeance and in hopes that "something big" is behind it all, decides to pursue the case.