“The Mousetrap,” a murder-mystery written by the novelist and playwright Agatha Christie, opens at the Ambassadors Theatre in London. The crowd-pleasing whodunit would go on to become the longest continuously running play in history, with more than 10 million people to date attending its more than 20,000 performances in London’s West End.

When “The Mousetrap” premiered in 1952, Winston Churchill was British prime minister, Joseph Stalin was Soviet ruler, and Harry Truman was president. Christie, already a hugely successful English mystery novelist, originally wrote the drama for Queen Mary, wife of the late King George V. Initially called “Three Blind Mice,” it debuted as a 30-minute radio play on the queen’s 80th birthday in 1947. Christie later extended the play and renamed it “The Mousetrap”—a reference to the play-within-a-play performed in William Shakespeare’s “Hamlet.”

On November 25, 1952, 453 people took their seats in the Ambassadors Theatre for the London premiere of Christie’s “Mousetrap.” The drama is played out at “Monkswell Manor,” whose hosts and guests are snowed in among radio reports of a murderer on the loose. Soon a detective shows up on skis with the terrifying news that the murderer, and probably the next victim, are likely both among their number. Soon the clues and false leads pile as high as the snow. At every curtain call, the individual who has been revealed as the murderer steps forward and tells the audience that they are “partners in crime” and should “keep the secret of the whodunit locked in their heart.”

Richard Attenborough and his wife, Sheila Sim, were the first stars of “The Mousetrap.” To date, more than 300 actors and actresses have appeared in the roles of the eight characters. David Raven, who played “Major Metcalf” for 4,575 performances, is in the “Guinness Book of World Records” as the world’s most durable actor, while Nancy Seabrooke is noted as the world’s most patient understudy for 6,240 performances, or 15 years, as the substitute for “Mrs. Boyle.”

“The Mousetrap” is not considered Christie’s best play, and a prominent stage director once declared that “‘The Mousetrap'” should be abolished by an act of Parliament.” Nevertheless, the show’s popularity has not waned. Asked about its enduring appeal, Christie said, “It is the sort of play you can take anyone to. It is not really frightening. It is not really horrible. It is not really a farce, but it has a little bit of all these things, and perhaps that satisfies a lot of different people.” In 1974, after almost 9,000 shows, the play was moved to St. Martin’s Theatre, where it remains today. Agatha Christie, who wrote scores of best-selling mystery novels, died in 1976.