In post-World War II Tokyo, Eddie Kenner (Robert Stack) is on a U.S. Army special assignment to investigate a murderous clique led by ex-soldier Sandy Dawson (Robert Ryan). Kenner ingratiates himself with Dawson and his inner circle, gaining their trust while starting a relationship with Mariko (Shirley Yamaguchi), the wife of a murdered gang member. But the sinister Dawson suspects there's a traitor among them when the police are tipped off about a planned robbery.