Adapted from a play by Achmed Abdullah and David Belasco, a Chinese enforcer marries the daughter of his friend he executes.
In San Francisco's Chinatown a tong declares war after a murder. A fortune-teller sees the funeral of Sun Yat Ming (J. Carroll Naish). At the tong council Nog Hong Fah (Dudley Digges) tells hatchet man Wong Low Get (Edward G. Robinson) that Sun Yat Ming committed murder. Wong says that Sun is his best friend; but the tong demands that Wong kill Sun. Sun makes his will, leaving everything to Wong. Wong calls on Sun, who asks him to marry his daughter Toya after she grows up. Then Wong executes Sun with his hatchet.
Fifteen years later customs have changed. At his office Wong tells Nog that he hopes Toya will consent to marry him. Toya (Loretta Young) dances with Harry En Hai (Leslie Fenton), who tries to kiss her. On her birthday Wong gives Toya a diamond bracelet and a betrothal ring. She accepts and kisses Wong. On their wedding day a tong war is declared. All on the council agree on war except for Wong, who recommends negotiating with Sacramento. Nog brings in bodyguards from New York. Wong assigns one to Toya, who tells bodyguard Harry that she is married. Wong takes the other bodyguard to the docks and finds a dead man, while Toya tells Harry that she won't dance with him or let him kiss her. Wong takes his hatchet to Sacramento, while Toya goes out dancing with Harry. The Chinese agree with Wong; but Malone objects. A newspaper reports a crook was killed with a hatchet, and the tong returns to peace. Wong and Nog find Toya kissing Harry, who asks her to go to New York. Wong knocks the gun out of Harry's hand with his hatchet. Toya stops Wong from killing Harry, saying Wong promised her happiness, and she loves Harry. Wong makes Harry promise to make Toya happy. Harry and Toya leave, and Wong cries.
The council expels Wong from the tong for having lost their respect. A note suggests that Wong fill a coffin with the lover of his wife. Wah Li finds Wong working in a field and gives him a letter from Toya, saying she loves Wong and is suffering. Wah Li says that Harry was caught selling opium, and both were deported to China. Wong gets his hatchet and shovels coal on a steamer to China. He finds Harry coming out of an opium den, where Toya works. Wong takes Toya from the woman who bought her from Harry. Wong throws his hatchet into a painting, but it kills Harry on the other side of the thin wall.
This drama explores the violent aspect of Chinese society in America which still maintains some of its ancient culture amid modernization.