Murder mystery begins longest run in history On this day, Nov. 25, in 1952, Agatha Christie’s murder-mystery play “The Mousetrap” opened in the West End of London and is the longest continuously running play ever.

In the play, the owners and visitors of a snowed-in guest house get a visit from a police officer who informs them that a woman has been murdered and the killer is at large. After one of the guests is found dead, the group realizes that the killer is already there. The play has a twist ending, which at the end of every performance the audience is asked not to reveal.