Irene Roma, a young Russian teacher at an American mission near Shanghai, is entrusted with an amulet by her brother Peter Roma, who has been wounded by Igor Sargoza, a discredited Russian secret agent, who is aware of the amulet's value. Needing a Russian passport in order to leave Shanghai, Irene presents her problem to Howard Barclay, an English friend of her brother's, and his friend, Johnny McGinty, an American newspaper photographer. Barclay suggests that McGinty marry her, thereby giving her his American citizenship. A Chinese friend sends the bride a beautiful mandarin figure, to be used as an incense burner but Johnny decides to use it as a hiding place for the amulet. Barclay learns that the marriage does not make Irene an American citizen, but he obtains a Chinese special passport and the three friends, after beating off another attack by the Sargoza gang, reach the Japanese merchant ship that is to take then to safety. On ship they encounter Fuji Yokahama who has learned the hiding place of the amulet.
