Luk Chan (Sessue Hayakawa) is the top hatchet man for his tong, or gang, in San Francisco's Chinatown. He is in love with pretty Sen Chee (Helen Eddy), whose father (Toyo Fujita), a wealthy merchant, is being blackmailed by the gang. Chan is ordered to kill Sen Chee's father, but he can't bring himself to ruin his sweetheart's life. So he refuses and is condemned to death himself. He saves the girl from the tong's leader, and they are fiercely pursued over rooftops by the gang. After several near-calamities, they escape and together board a ship headed for China.