Ma Delano and her family--Jennie, Joe, and Harry--operate a penny arcade on an amusement pier over which Mitch McKane, a bootlegger doubling as a sideshow operator, wields an influential hand. Angel Harrigan, a barker who works for Mitch, incurs his wrath because Jennie prefers Angel to him. Angel then quits working for Mitch and is hired by Ma, who hates Mitch because liquor ruined her late husband's life and she fears that it will do the same to her favored youngest child, Harry. Unknown to Ma, Harry has been working with Mitch, and when Mitch is arrested on suspicion of murdering a cohort, he asks Harry to oversee his speakeasy until he gains his freedom. As he predicted, Mitch soon is released for lack of evidence, and when he discovers that Harry has been skimming profits from the speakeasy, plans to "get" him. That night, while a party is being thrown in honor of Mitch's return, he meets Harry in a darkened section of the amusement park. After arguing, Harry shoots him, then hides the body. Unknown to Harry, Jennie has seen everything from her bedroom window but tells no one. The next day, when the body is found, police Det. Sykes is suspicious of Harry, but Myrtle, a woman with whom Harry is involved, backs up his alibi by swearing that they were together on the beach all night. Sykes's suspicions then fall on Angel, who had once been convicted of a petty crime and was seen by the beat policemen at the park at around the time Mitch was killed. Meanwhile, Harry confesses to his mother, who places the gun Harry used in Angel's suitcase. Because she and Angel are in love and plan to marry, Jennie finally breaks down and reveals the truth about the murder as Sykes is about to place Angel under arrest. Despite his mother's desperate pleas, Harry finally confesses and is led away from the park. Crushed that her favorite is lost to her, Ma initially disowns Jennie but soon takes her back and re-hires Angel as her barker.