even in the 50s. do you think it s the best play you ve written? i don t know. other people seem to, anyway! and since then, it s been a fixture on the west end, with one veteran involved from day one agatha christie s grandson. it s a very important moment, but one thing i will tell you about this anniversary, it will not be the last. and to mark the landmark, there is going to be a second mousetrap on broadway. each summer, we have thousands of american tourists coming to the show during the summer season, and i think it s time we got on the front foot and took it there. and part of the mystique of this is there s never been a film of it. there are film rights, but they came with a clause they had to wait until the london production closed. 70 years on, they re still waiting. david sillito, bbc news, in london s west end. not only the longest running play, but the longest running