The Bloodhounds of Bath is a society that meets in a crypt to discuss crime novels. To their latest recruit they are simply a gaggle of dotty misfits, until one of them reveals that he is in possession of one of the world's most valuable stamps, recently stolen from the Postal Museum. Then theft is overtaken by murder when the corpse of one of the Bloodhounds is found in a locked houseboat, with the only key in the possession of a man with a perfect alibi. Burly detective Peter Diamond, head of the murder squad in Bath, finds himself embroiled in a mystery that in more than one sense evokes the classic crime puzzles of John Dickson Carr.