Directed by: Sidney Gilliat
Screenplay: Christianna Brand, Sidney Gilliat
Cast: Alastair Sim, Sally Gray, Trevor Howard, Ronald Adam, Judy Campbell
In a hospital during World War II, a mail carrier dies under unexplained circumstances. One of the nurses who was present claims that his death was not an accident, but a murder. Soon after, the nurse is also found dead. The police, led by Inspector Cockrill (Alastair Sim) of Scotland Yard, soon conclude that any of the five surviving members of the surgical team might have had a motive for the murders.
During his investigation, he uncovers a series of facts about most of those present that put them in his crosshairs and lead him to consider them all suspects, but he cannot accuse anyone with certainty. He must ultimately put one of the suspects in danger so that the killer falls into his trap.
