The Times Jumbo Cryptic Crossword Book 21: The World's Most Challenging Cryptic CrosswordSelected by The Times' Crossword Editor, Richard Rogan, this original collection will challenge even the most experienced crossword buff. The ultimate and only jumbo cryptic crosswords available, these puzzles will allow you to give the grey matter a real workout. With unique grids of 23 x 23 squares (in comparison to the standard 15 x 15 grid), they require serious word power and cryptic puzzling skill. Put your linguistic prowess to the test with