The Times Jumbo Cryptic Crossword Book 21: The world’s most challenging cryptic crossword (The Times Crosswords)This supremely challenging cryptic collection contains 50 jumbo sized, large grid puzzles, conceived to really challenge your word skills. Selected 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