A racketeer leaves his business, loses it, and is wounded trying to get it back; then he finds happiness in a monastery.
Johnny Sarto (Edward G. Robinson) complains about a murder and tells his gang at a table he is quitting and going to Europe. Flo Addams (Ann Sothern) helps Johnny pack but learns he isn't marrying her nor taking her. Johnny promises her a wedding and gets her a job in a nightclub. Johnny buys a diamond in London, a horse in Paris, and spends all his money before returning to his business after five years.
Jack Buck (Humphrey Bogart) says he is boss and has Johnny thrown out. Johnny learns that Flo moved to the Biltmore. She welcomes him and says she bought the nightclub. Johnny calls Willie the Knife (Allen Jenkins), who is hiding from Buck in a mental asylum. Wealthy rancher Clarence Fletcher (Ralph Bellamy) calls Flo, who has him drive Johnny and her. Gangsters follow them. Johnny tells Willie to round up a mob. Clarence beats up two gangsters. Johnny's men doubt he can take over Buck. Willie brings Mugsy (Richard Lane) to Johnny, who makes him talk. Johnny sells a better protection policy than Buck by force. Clarence invites Flo to his ranch, but she goes to Buck to make peace. Buck offers to meet Johnny. Flo goes with Clarence and calls Johnny to come get her, acting drunk. Buck sees Johnny arrive. In the car Clarence is knocked out. Buck makes Johnny go outside and get in a car. In the woods Johnny runs and is shot; but he staggers to a monastery, where Brother Superior (Donald Crisp) welcomes him.
Brother Wren (Charles D. Brown) tells Johnny how he can join. Johnny recovers and signs up as Brother Orchid. Johnny excels at milking by adding water and is given a flower plot. Johnny has a boy work for him and owes him. Brother Superior reprimands Johnny but forgives him. Johnny sees in a paper that Flo is to wed Clarence. Johnny gets a ride to the city with Brother Superior and calls on Flo, who comes in and faints. She explains and says she loves him. Johnny says he'll wed her. Brother Superior tells Johnny he couldn't sell the flowers because of Buck's protective association. Johnny tells him he is leaving. Clarence is angry but understands when Flo says she loves Johnny, who asks Clarence and three men to help the monastery by driving out Buck and his gang. They go and fight them. Police arrive and arrest Buck. Johnny tells Clarence he doesn't really love Flo, gets $300 from him, and sends him to her. Johnny gives the money to a woman washing the floor. In the final scene Brother Superior announces they can sell flowers again, and Johnny comes back.
The contrast between the violence and superficial values of gangsters compared to the charitable kindness of monks provides powerful drama and humor in this spiritualized gangster movie.