Manfredi, an habitual user of opium, is a piano player in a Chinese café. A wealthy tourist becomes interested in the young musician and sends him abroad to study. He promises Zuletta, his common law wife, that on his return he will marry her. Five years later he comes back, still addicted to the drug. Under its spell he is proclaimed a genius. Failing to make good his promise to Zuletta, he becomes infatuated with Margery Rhodes, a society girl, who comes to study music with him. So strongly is Margery influenced by her teacher, that she also acquires a taste for opium. John Hale, her lover, is in the secret service. Through the revengeful Zuletta, he learns that Manfredi conducts an opium joint. Hale has the place raided, just in time to save Mergery from a fate worse than death.