In revolution-torn China, American mercenary O'Hara is entrusted with a perilous mission, to get arms for the helpless authorities in a province ravaged by warlord General Yang. On the train to Shanghai, he meets Judy Perrie, whose father is in league with Yang. Will Judy regret agreeing to lure O'Hara to his doom, and if so, can she make it up to him? The balance of power seesaws to a perilous conclusion.