The legendary Agatha Christie, playwright behind ‘The Mousetrap’, thought that her murder mystery would only run for a few months. How wrong she was. After making its West End debut in 1952, the play celebrated its 250,000th performance in early 2013, and is still going strong. We speak to two ladies who have played the piece’s Miss Casewell in different decades: Denise Silvey, who last took the stage in the play’s forty-third and fiftieth years, and the current Miss Casewell, Natasha Rickman (whose mother, Miranda Bell, also played the part in the thirty-third year of the production). Together, they give Time Out an exclusive insight into the timeless appeal of the world's longest-running theatre show.