Clifford Odets adapted Charles Booth's novel about an American, who is caught by a Chinese warlord carrying money for guns to oppose him.
O'Hara (Gary Cooper) sympathizes with the refugees who couldn't pay the taxes in the town General Yang destroyed, and he is told to take money for guns to Wu by plane, not by train. Peter Perrie (Porter Hall) gets his daughter Judy Perrie (Madeleine Carroll) to lure O'Hara onto the train. O'Hara enters her compartment and embraces her. She is scared because he opposes the military dictatorship of Yang, and he kisses her. She warns him as the train is stopped; but General Yang (Akim Tamiroff) and his soldiers board. O'Hara says he believes in the people and tells Yang his days are over. Yang asks O'Hara for the money and uses his sword to get it. Pete will take the money to Brighton. O'Hara slaps Judy as he leaves with the soldiers.
At a Shanghai hotel Brighton (William Frawley) drinks while waiting for O'Hara. Judy checks in with O'Hara's monkey and tells Pete not to bet on horses. Wu (Dudley Digges) calls on Judy and asks where O'Hara is. O'Hara tells Yang he failed the people who want Yang off their necks. Pete buys two tickets on a ship. Judy and he catch Leach (J. M. Kerrigan) searching his room for the money. She learns that Pete is not picking up the shipment and rips up his tickets, threatening him if O'Hara dies. O'Hara overpowers a soldier and escapes by swimming, but he is wounded. Wu treats him, and Chen says they can't trust O'Hara again. Wu says O'Hara was lonely. O'Hara wants to go after Judy and Pete. Wu gives him a pistol and opens the door to reveal Judy. She tells O'Hara she is glad he is alive, and he asks her where the money is. She offers the money for a $2,000 bonus for her father; but Pete shoots O'Hara in the hand and is killed. Leach holds a gun on O'Hara, while he calls Wu, who arrives with a gun. O'Hara takes Leach's gun; but Yang comes in with armed men and asks for the money.
Yang takes them all on his boat, including Brighton passed out. Judy offers to sacrifice herself for O'Hara and Wu; but Leach tells Yang she is going to lie. O'Hara tells Judy they could have had a circle of light and warmth. Brighton asks for a drink and cuts open a suitcase of money. He knocks out a lamp and shoots a soldier; then he stabs Yang and is knocked out. O'Hara says Yang's men killed him and argues with Yang. Yang tells his men they must die with him, and the whites and Wu too. O'Hara argues that someone must tell his story, and after Leach is shot, persuades Yang to spare Judy, Wu, and him. Yang gives an order, and the soldiers shoot each other. Then Yang dies. Wu says that Yang was talented but very corrupt.
Set in China's contemporary civil war, an American opposes militarism with more guns while hoping for democracy. His danger is increased when he is foolishly lured by a woman. The audience-pleasing deus ex machina ending kills the bad Chinese, allowing one good one to make a wise comment.