A Chinatown tourist bus is caught in the middle of a tong war, and in the resulting confusion, society woman Joan Fry is left behind. Chuck Riley, the white leader of a tong faction, pulls her from the dangerous streets and keeps her overnight in his apartment. The following morning, Joan leaves, returning later with friends; Chuck again saves her life. Joan falls in love with Chuck and moves in with him, renouncing her former life. She tries to get Chuck to reform, and he throws her out. Joan wanders the streets, and Boston Charley, Chuck's rival, gets her drunk and sends her back to Chuck with a humiliating letter pinned to her frowsy sweater. Chuck, moved by Joan's condition, wrecks his dance hall and leaves Chinatown with her, looking for a new beginning and a brighter tomorrow.