In the office of Major Northfield, the quartermaster of the Pacific Coast, a leak has been discovered which may endanger the safety of American transports that are secretly carrying troops across the Pacific. Nara-Nara, a Japanese detective, is assigned to the case because his country has guaranteed safety to these transport ships. Nara-Nara believes that Northfield is guilty, although in reality it is Northfield's secretary Kitty Little, a girl of German ancestry, who is passing information to Dr. Ebell Smith, a German agent. Nara-Nara falls in love with Kitty, but soon after discovers that she is the leak in the quartermaster's office.

Joan Fry, a society woman, falls in love with Chuck Riley, the white leader of a powerful gang in Chinatown, and he quickly drags her down into the depths with him. But seeing her so much in love with him causes him to realize he is in love with her, and he determines to lift her up again. "Boston" Charley, the rival gang-leader, has other plans.