The story follows Thomas Accardo (Tomas Milian), a lawyer and godson to San Francisco mob boss Don Antonio Macaluso (Martin Balsam). After a prison stint, Thomas tries to go straight, but his departure triggers a violent gang war as rival factions see it as a sign of weakness. Thomas eventually returns to the "family" to defend his Don.

Unusually for the genre, it was filmed primarily in San Francisco and Albuquerque, New Mexico, before shifting to Sicily for the finale. The film features a well-regarded atmospheric score by the famous Italian composer Riz Ortolani.