After blacking out from an all-night drinking binge, dock worker Bobo (Jean Gabin) wakes up in a decrepit shack on a San Pedro Bay barge. He's hired to sell bait by the barge owner and fisherman Takeo (Victor Sen Yung) who informs him that local bar-fly Pop Kelly (Arthur Aylesworth) was strangled to death the night before. Bobo meets up with his friend Tiny (Thomas Mitchell) and Nutsy, the town watchman and amateur philosopher (Claude Rains) at a local boardinghouse. Despite assurances from Tiny that he didn't hurt anyone during his blackout, Bobo worries that he may have killed the man, due to violence in his past. As Tiny and Bobo talk, Nutsy realizes that Bobo is in possession of Pop Kelly's hat. That night Bobo plans to leave town but ends up rescuing Anna (Ida Lupino), who tries to drown herself in the surf.