To research the criminal element of New York City's Chinatown, writer Frank Theydon enters the underworld, where a gang of thugs place him in peril. Although he is saved by Evelyn Forbes and her father, he later sees Forbes entering his neighbor's flat. When the neighbor, a woman, is found murdered the next day, Frank suspects Forbes, who insists on his innocence. Although Forbes is arrested for the murder, the police later learn that he is in danger from a "Tong," a secret Chinese society of criminals whose leader he has enraged. Forbes is given special protection, but Evelyn is tricked by a false telegram and, with her mother, abducted. In an attempt to rescue her, Frank is captured by the thugs and taken to the den where Evelyn and her mother are being held. He fights the thugs unsuccessfully and is about to be killed, when a rival Tong group attacks, setting fire to the building. Frank is able to rescue Evelyn and her mother, and after a series of events, the police find the real murderers, and Evelyn and Frank are united in love.