In the 1960s, Richard Kuklinski (Michael Shannon) marries Deborah (Winona Ryder) and the couple have two daughters. Kuklinski keeps secrets from his family. He works dubbing pornographic films, which he then supplies to a mob operated syndicate, but he tells his family that he dubs The Walt Disney Company cartoons. Kuklinski is also deeply troubled. As a boy he was the subject of brutal beatings from his immigrant Poles father, shaping Kuklinski into an emotionally disturbed and intensely violent man. A man insults him after a game of pool so Kuklinski follows the man to his car and murders him by quickly slashing his throat.