In Paul Halter's The Fourth Door, the impossible becomes reality. A haunted room. An unbroken seal. A murder victim whose very identity is an enigma. And then, a second death in a house surrounded by untrodden snow. Both crimes defy reason?but master detective Dr. Alan Twist reveals that even the most baffling mysteries have rational explanations.

This international bestseller is a masterpiece of intrigue and misdirection, hailed as the French answer to John Dickson Carr and a modern rival to Anthony Horowitz (The Twist of a Knife). Fans of Sophie Hannah's Poirot mysteries and the layered puzzles of Knives Out will relish this thrilling, twist-laden tale. Winner of the Prix du Roman Policier, Halter cements his place as a titan of the locked-room genre.