Chinese merchant Wing Lung and Elizabeth Mendall, an American, marry and have a son named Jang Lung. Because Elizabeth wants Jang Lung to be raised as a Christian, Wing Lung locks her in the cellar and she becomes insane. Jang meets Marcell Matthews at an Eastern university, and she returns with him to San Francisco to be married. After visiting Chinatown, however, she is disillusioned and breaks off the engagement. The enraged Jang sells Marcell to a marriage broker but tries to rescue her when he learns the true identity of his mother. In the attempt, Jang is mortally wounded, but becomes reconciled to Marcell and his mother before his death.