The strange happenings at Wonderland, an English summer holiday camp, give sleuth Nigel Strangeways one of the toughest problems of his career. When you have over 400 suspects milling around at will, it is hard to pin the right one down. However, Strangeways does it in a surprising last minute denouement in which the criminal is forced to show his hand. This is a unique mystery story, despite the required ingredients of suspense, spies, action and all-clues-above-board detection---there is something peculiar about the corpses. The villain, who calls himself the Mad Hatter, is a prankster who perpetrates a series of peculairly diabolical practical jokes. Strangeways' unmasking of him is aided by Mr. Thistlethwaite, a Pickwickian Oxford tailor on vacation, and by Paul Perry, a Mass-Observer who knows his Auden.