Test your powers of logic with these challenging Su Doku puzzles.

This is the seventh title in the Fiendish series - the latest volume of quality previously unpublished puzzles from the puzzle providers to the Times.

You don't need to be a mathematical genius to solve the puzzles in this collection of Fiendishly difficult puzzles, it is simply a question of logic.

Since the first Su Doku puzzle appeared in The Times in November 2004 they have become a phenomenon, with over 5 million copies of the Times Su Doku series sold worldwide.

The puzzles in the collection are of the highest quality - from the puzzle suppliers to The Times. Perfect for the advanced solver in need of a constant supply of ultra-difficult puzzles, and guaranteed to provide hours of mind-stretching entertainment.