Wealthy industrialist Charles Collison is found bludgeoned to death shortly after his son, Geoffrey, and nephew, Arthur Cross, return from World War II. As the principal beneficiaries of Charles' will, both men are suspects. Inspector James is called in to investigate and thinks he knows which of them is guilty.
Arthur Cross, who survives a concentration camp which leaves him conscienceless, returns to England to share, with his cousin, in an uncle's benevolence and affection and the promise of a substantial inheritance. Wanting his share now, rather than later, Cross plans ingeniously and infallibly his uncle's murder, waits many months before be can effect it with an alibi which the police cannot perforate much as they dislike him. But a chance witness, a girl of easy virtue, follows him down after the case is closed, causes him to kill again spontaneously and less successfully, eventually leads to his desperate undoing. Accomplished.