An ambitious fighter gains success on the rough side of old San Francisco and falls in love with a society woman who owns the newspaper.
In 1854 on the Barbary Coast of San Francisco in a saloon at night Spider Burke (Barton MacLane) throws a preacher out. A sea captain says he needs three sailors so that he can depart. Bat Morgan (James Cagney) walks in, and a man says now they are only short two. Bat asks how much a room is and says he will try the gold fields. Slugs Crippen (Joseph Sawyer) follows him upstairs and knocks him out with a club. He carries Bat outside, takes his money belt, and puts him in a boat that he rows. Bat wakes up and fights with Slugs. They fall into the water, and Bat gets back in the boat. He staggers ashore exhausted. Solly Green (George E. Stone) hears something and goes out with a lamp. He helps Bat come to his place. Solly asks Bat where he went and explains that they Shanghai men by making them work as sailors. Solly warns him about the Shanghai Duck, but Bat says he will get him. Solly says that the one who digs a grave for somebody else usually falls in it himself. Bat says he follows the way of dog-eat-dog. Solly says they get $250 a man. Bat asks why he did not turn him in. Solly says he sells merchandise, not men. Bat asks for an old chair and pulls off a leg to use as a club.
Bat waits for Slugs who has captured another man, and he knocks him out with his club. He takes a knife and gets his money belt back. Bat takes unconscious Slugs and the other man in a boat out to a ship, where he sells the two men.
In a gambling hall Paul Morra (Ricardo Cortez) is dealing cards. Bat says he is too lucky. Solly advises Bat to keep his money. Bat bets $100 and stops the dealer from cheating. Outside Burke learns from Shanghai Duck (Fred Kohler) that Slugs is probably dead.
Reformers Judge Stephen Crawford (Robert McWade) and Tribune editor Charles Ford (Donald Woods) go in the gambling hall. Paul sees Crawford and tells Belle Morra (Lili Damita) to pass the word that everyone is to clamp down. The Duck who has a hook instead of a hand comes in. Bat asks Paul for a job there, but the dealer says no. Bat is leaving when the Duck uses his hook on Bat’s shoulder, and a fight begins. Ford and Crawford tell Morra to stop the fight as the owner of the place; but he tells them to stop it if they can. When the Duck picks up a chair, Solly intervenes to prevent that. Finally Bat chokes the Duck dead, and men cheer him. Crawford tells them to get Bat to a doctor. Ford introduces himself to Bat and thanks him for his service to the city. Solly says he will take Bat to a pharmacy. Paul offers Bat a job.
In the Tribune an editorial by Ford praises what Bat did. In the newspaper office the owner Jean Barrat (Margaret Lindsay) comes in and praises Ford’s work. She says she wants the Tribune to fight. Her father was a fighter who was killed on the Barbary Coast. She warns Ford he is in danger. Ford says San Francisco will be a metropolis. Crawford comes in and compliments Ford. He advises him to use his influence to help stamp out corruption.
Solly gives Bat a suit from his second-hand store. In the gambling hall Bat throws out an unruly customer. Paul tells Bat the profits for the night were about $30,000. Belle shows Paul an editorial criticizing crooked gambling halls. Paul says that Jim Daley at City Hall will not stand for that but will try to run them out. Bat learns that Daley lives at International House.
Bat takes Solly with him to meet Daley. Bat sees Ford and Jean and asks to be introduced to her. Solly tells Bat he is not good enough for the lady. Bat says he will make himself the biggest man in town, but Solly says she will still be a lady. At the bar they have Frisco punch, and Bat offers the bartender McClanahan a job. Bat goes over to Jim Daley (Joseph King) and offers him a proposition. Daley gives him champagne. Bat says that Ford will rouse the supervisors. Bat asks to be put in charge of the Coast, and he says Daley will build him a place better than Morra’s.
Bat holds a meeting at Morra’s Palace at 5 a.m. Bat says they are going to clean up the town. He tells them to pay him, and he will pay off the others in order to “buy up all the soap.” Burke says he will not obey Bat and walks out. Others agree, and Daley puts Morgan in charge of the Coast. Paul asks Bat to be his partner, and Bat says he is going to build a place for wealthy people. Paul drinks with Bat and Daley.
Bat buys $100 suits for Solly and himself. Bat opens the Bella Pacific and throws away the key. The plush gambling hall has a marble bar and is full of better people. Burke tells Bat that his place was raided twice in the last week. Burke joins and gives Bat a bag of gold dust. In his office Daley tells Bat that they have to get rid of Ford. Bat says he likes him. Daley suggests a framed duel. Bat refuses to obey Daley and tells him to leave Ford alone.
Jean comes in to see Bat Morgan, who introduces her to Solly, his best friend. Solly says Bat is going to be the biggest man in the town and withdraws. Bat tells Jean he wants to know her better. She says Burke has challenged Ford to a duel and that it must be stopped. Bat promises to protect Ford. She thanks him and shakes his hand.
At a bar Burke tells how he will kill Ford at dawn by cheating. Bat tells a man to wait outside, and he goes in. He goes to Burke’s room and tells him he is not fighting Ford. Burke resists, and Bat knocks him out. He puts Burke outside the door. Outside Bat tells the man to go and tell Ford the duel is off because Burke is afraid to fight.
In a buggy Jean asks to see Bat at the side entrance. Solly tells the bartender that Burke wants to kill Bat. Outside Bat is talking with Jean. Solly comes over to warn him just as Burke shoots at Bat. However, Solly is shot. Jean stops Bat from shooting at Burke, and Solly dies in Bat’s arms. Two men find Burke drowned.
At a cemetery Jean joins Bat at Solly’s grave. He thanks her for attending the funeral. They walk and sit down where they can see the city. He says she has been sheltered. He says he has to look out for number one. She disagrees with his “dog-eat-dog” philosophy. She asks him to help build the city and says he is tearing it down. He says he does so to put up bigger buildings. He says he wants to be more than friends, but she says that is not possible. He says she is the only one who means anything to him.
Judge Crawford publishes an announcement that a season of grand opera is beginning at McGuire’s Opera House. Jean tells him she likes it and says she is coming on opening night. She is going to see Bat, and Crawford tells her she should not associate with him because he is part of the Barbary Coast that took her father’s life. She says Bat has a worthwhile side, and she chooses her own friends. They go to her home and find Bat there. Crawford refuses to shake his hand and leaves. She says she will keep seeing him. Bat says he is in love with her. She says she is sure too, and they kiss. She says that is the beginning and end of it. He wants to marry her; but she says they are too different. He says she will marry him someday. Outside Crawford stops Bat and orders him to keep away from Jean, or he will shoot him like a dog.
In the Bella Pacific Bat tells his manager Graber (Robert Strange) to close the place because they are all going to the opera. He hands him tickets for everyone. At the opera Crawford sees the people from the Barbary Coast. Bat smiles at Jean and sits down. Paul and Belle sit in the box behind Crawford and his wife. Paul tells Crawford to apologize to Belle. Crawford complains, and Paul shoots him. Men grab Paul, and Crawford has died.
Ford reports Crawford’s murder in the paper and that an ugly mood has developed with vigilantes. Bat reads the paper and throws it down. Belle asks Bat to get Paul out. Bat promises that he will.
In the street a mob listens to speeches about hanging Paul Morra. Ford agrees that Morra is guilty and should be punished, but he argues for upholding the law with courts and juries and judges. People cheer him. Ford learns that Daley has freed Morra. Ford goes to a bar and tells Daley that he will expose him as a corrupt politician. Daley grabs Ford’s coat, and Ford knocks him down. Daley pulls out a pistol and shoots Ford in the back as he is leaving.
Bat learns that Ford is in critical condition, and Daley is in jail. Bat says to keep him there. A doctor is caring for Ford, and Jean sits by him. Ford tells her to keep the paper going. The doctor indicates he died.
Jean goes to the paper and orders that her father’s article on the vigilantes be printed. Bat comes in and tells Jean he is sorry about Ford. He says it will change everything with them, but she says no; they are still on opposite sides. She is ashamed of having said she loved him. She never wants to see him again and tells him to get out. He leaves. Outside he notices the vigilante meeting announced for that night.
At the vigilante headquarters their leader William T. Coleman (Addison Richards) makes a speech of what they should do. Some vigilantes knock on a door and tell Paul he is wanted at vigilante headquarters. A crowd gathers in the street, and Coleman tells the jailer that they came for the prisoner Daley. Holding guns they walk Daley outside,
Some men ask where Bat is and decide to go to the newspaper. In their hall the vigilantes tell Morra and Daley that they have been found guilty of murder, and both are to be hanged. Daley pleads it was self-defense.
McClanahan tells Bat that the vigilantes are going to burn the town, starting with the newspaper office.
As a crowd cheers, nooses are put around the necks of Paul Morra and Jim Daley. Then each is pushed out of a high window. The crowd begins to leave. Men attack the newspaper office and begin destroying things. Bat comes in and shouts for them to stop. He says they must go back to the Coast to prevent it from being burned down.
The vigilante leader Coleman tells the mob to burn the Barbary Coast to the ground and bring in Bat Morgan. They cheer and follow him with torches and clubs. They shoot, break windows, and throw in torches. People come out with their hands in the air. In the Bella Pacific they get guns, but Bat tells Graber it is no use. He tells them to get out because the vigilantes have right on their side. Graber calls him a “double-crossing rat,” and Bat knocks Graber down. Graber gets up and shoots at Bat’s back, and he falls. Others shoot at the approaching vigilantes. They are overcome by the vigilantes and leave with their hands up. The place is set on fire.
McClanahan goes to Jean and tells her that they took Morgan and asks her to help him. They plan to hang him. He says he saved her paper and tried to keep the mob from burning the town. He was shot for trying to keep the Coast from killing the vigilantes. When she realizes that he was shot, she reacts.
At the vigilante headquarters Coleman tells the Barbary Coast people that they will be put on the first ship. He tells Bat Morgan to stand up to hear his sentence. He is to be hanged for being responsible for what the Coast people did. Jean comes in and explains how Bat did the right thing and tried to stop the killing. She asks them to show him mercy. Coleman asks the committee to vote again. Bat tells Jean he finally saw things her way and is getting hanged. He asks her not to be ashamed of loving him. She is not ashamed. Coleman tells them Bat is given his freedom, but he must leave. Bat says he made his place there and is only guilty of trying to make good in his own way which he learned was wrong. He wants to do right with her help, but Coleman says he could never have the right “background.” Jean says he would have her. Coleman says they will parole him in her care. Bat says he has a job ahead of her, but she won’t regret it.
This melodrama portrays a brutal frontier situation where violence erupts easily on the wild side of a city. A fighting man manages to become successful by working with a corrupt politician, but the love of a more sophisticated woman eventually helps him to realize that honesty and caring about others are more important and eventually produce better results.