The Cain's Jawbone Book of Crosswords (Paperback)

Before Edward Powys Mathers wrote the world's most difficult literary puzzle, he was a cryptic crossword creator. Under his pseudonym 'Torquemada', his puzzles would taunt readers for days. He created his first cryptic crossword puzzle in 1924 and went on to set them for the Saturday Westminster and the Observer for the next 15 years. His true identity was only revealed when he died in 1939.

As well as earning the reputation for setting the world's toughest crosswords, Torquemada - or 'Torq' as he was often referred to - was also delightfully creative: with many puzzles written in perfectly constructed verse or delivered as mini-narratives to their solvers. There's even a version where the clues are knock-knock jokes. This selection of Torquemada's best crosswords was originally published in 1942 and this edition contains tributes to his life and achievements, including one by his widow, R.C. Mathers.

The successful revival of Cain's Jawbone has inspired a new generation of puzzle solvers. Here is the next challenge for Torquemada's fans - dare you take it on?

Health warning: These crosswords are extremely difficult and not for the faint-hearted.