Happy MacDonald's nightclub is a world of gambling, infidelity and casual encounters. One night, millionaire Michael Rand, whose mother shot and killed his unfaithful father, is one of the customers. His drinking attracts the attention of showgirl Ruth Taylor, who tries to cheer him up. Edith Blair, Michael's father's mistress, happens to be seated at a neighboring table. After Ruth leaves to prepare for the next floor show, Edith tells Michael about his father's unhappy life with his mother. Michael, now very drunk, makes a scene and Happy knocks him out with one punch. Happy also has a bad marriage. While he flirts with the showgirls, his wife Jill is involved with Klauss, the choreographer. When Happy is threatened by gangsters who want him to use the liquor that they sell, Jill sees an opportunity to get rid of Happy and empties his gun of bullets. Tim the doorman is concerned about the condition of his wife who is in the hospital. Meanwhile, Ruth and Michael are becoming better acquainted as she takes care of his bruised face and he defends her against womanizer Ed Powell. Unexpectedly, Michael's mother comes looking for him. He confronts her with her neglect of his father and himself and she admits that she only married for money and never wanted a child. As night becomes day, Michael asks Ruth to go to Java with him, Happy discovers Jill with Klauss, and Tim learns that his wife has died. Tim sadly leaves for the hospital, but at the door, he is shot and killed by the gangsters gunning for Happy. Warned by the shots, Happy draws his gun, but it has no bullets and Jill dies with him when the gangsters shoot them both. Ruth and Michael witness the shooting and are about to be shot themselves when the beat policeman bursts in and kills the gangsters instead. Now that the sun is up, Ruth and Michael board the boat for Java.