"If you're ready for an extra-hard, old-time challenge, have at it!"-- Will Shortz

From the creator and publisher behind the viral sensation Cain's Jawbone: A Very Novel Mystery, is a collection of 112 difficult cryptic crossword puzzles.

Before Edward Powys Mathers wrote the world's most fiendishly 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.

For many years cryptic crosswords were simply known as puzzles in the 'Torquemada style'. This selection of Torquemada's best crosswords was originally published in 1942 and contains three short accounts of Torquemada's life and achievements, including one by his widow, R.C. Mathers as well as a foreword by the crossword puzzle editor for the New York Times, Will Shortz. The successful revival of Cain's Jawbone has inspired a new generation of puzzle solvers.

Here then is the next challenge for Torquemada's fans - dare you take it on?