Pierre Herry is on the run, suspected of a double murder, but also from the memory of the circumstances in which two impossible crimes were committed in the ruined castle which is the hereditary seat of the Comte de Saint-Luce, an old big-game hunting friend from the past. Herry insists he is not guilty of the murders of which he finds himself accused, but claims they were committed right before his eyes in a way that defies explanation… and how can he defend himself if he cannot explain what happened? The inexplicable disappearance of another guest, threatening letters, and the howling of an unknown beast all serve as pieces in the puzzle, and examining magistrate M.Allou explains everything in this masterpiece of French locked room literature.