In the 1930s Edward Powys Mathers, AKA Torquemada, released Cain's Jawbone, the world's most difficult literary puzzle—a murder mystery whose pages are out of order, challenging the reader to arrange them to find out who died and how. Cain's Jawbone Book of Crosswords collects 112 challenging puzzles by Torquemada, the most influential early puzzle-setter.