Bob, a young sailor, lands in San Francisco, California, and unwittingly becomes involved in drug smuggling activities when he is sent to deliver opium to Wong Chang, a tong leader. A rival gang waylays Bob, steals the package, and leaves him stranded in the country. Bob finds work in a store and falls in love with Ruth Ketchell, forgetting Wong Chang's daughter, Mui Far, who loves him. Wong Chang finds Bob and returns him to the ship's captain, who beats the sailor for allegedly stealing the opium. The tong kidnaps Ruth and threatens to kill Bob, but Mui Far comes to their rescue. Realizing the futility of her love, Mui Far briefly considers suicide, but decides instead to accept the man Wong Chang has chosen as her husband.