The ideal gift for su doku enthusiasts. If you like to live dangerously and push beyond your mental comfort zone, steel yourself for The Times' toughest Ultimate Killer puzzles. A bumper collection of more than 360 puzzles for hard-core solvers. Selected from The Times these puzzles will challenge t...

The ideal gift for su doku enthusiasts. If you like to live dangerously and push beyond your mental comfort zone, steel yourself for The Times' toughest Ultimate Killer puzzles. A bumper collection of more than 360 puzzles for hard-core solvers. Selected from The Times these puzzles will challenge the sharpest minds.