Police Captain Bonavia (Balsam) arranges the release of a criminally insane prisoner, Michele Lipuma, who immediately sets about settling a score with a local construction magnate, Ferdinando Dubrosio. As Bonavia follows Lipuma's initial movements, it becomes clear that Bonavia orchestrated his release for that outcome. Lipuma's attempt to kill Dubrosio fails—Dubrosio was tipped off somehow and left three gunmen in his place...all of whom, including Lipuma, end up dead.