The killer in Agatha Christie’s play The Mousetrap is revealed to be Detective Sergeant Trotter. Throughout the play, the characters are trapped in a guest house during a snowstorm, and one by one, they become suspects in a murder investigation. The plot thickens as secrets are uncovered, and the tension builds until the final reveal.
Detective Sergeant Trotter, who initially appears to be investigating the case, is actually the murderer. His true identity is connected to a past crime involving the Longridge family, and he seeks revenge. The play’s famous twist ending has been kept a secret by audiences for decades, as they are traditionally asked not to reveal the killer’s identity after seeing the performance.