Shanghai, International Settlement, 1925. At a Chinese opera, Jake Greenberg, an American expatriate sits in a choice private box. Suddenly the door opens, gun fire booms out, and two people with him are dead. But the police cannot go beyond its borders to find the killer. Jake steps into that breach. The search for the killer leads to a half-crazy Chinese warlord, a glamorous film star, and a yet-to-be famous Communist leader, Chou En-lai.