The Times Ultimate Killer Su Doku : 120 Challenging Puzzles from the Times

For those who like to live dangerously and push beyond their mental comfort zone, steel yourself for The Times' toughest Killer collection yet. Prepare for the extreme mental challenge of 100 Deadly-level Killer puzzles, including, for the first time ever, 20 Extra Deadly, to really test your limits: thjs is the only place you'll find such a torturous collection in a single book. The Times Ultimate Killer Su Doku is not for the fainthearted. The puzzles use the same 9x9 grid as Su Doku, and