On November 25th, 1952, Agatha Christie’s The Mousetrap opened in a still-sooty, post-war London — and never stopped running. London Calling strolls down West Street to tell the tale of the world’s longest-running play: its famous first night, the legends behind the “Holman performances,” the stars who got their start, the stubborn little clock that’s ticked through seven decades, and why the curtain can never quite fall. A whodunnit that became a what-on-earth-keeps-it-going.