The first book of the utterly addictive number-placing puzzle.
Su Doku, the crossword without words, is taking the puzzle world by storm. Literally translated, Su means number and Doku means place.
Su Doku is a number grid made up of nine large squares, each divided into nine smaller squares. Between three and four numbers are already provided in each of the smaller squares. The aim is to fill the grid so that every column, every row and every three by three box contains the digits one to nine.
This book contains over 100 unpublished puzzles arranged in four levels of difficulty - easy, mild, more difficult and fiendishly difficult. Since The Times started to publish Su Doku, they have received an enormous number of enquiries about the puzzle and the availability of books.
Remember: you don't need to be a mathematical genius to solve these puzzles; it is simply a question of logic.
Wayne Gould, 59, the brains behind Su Doku, was formerly a High Court judge in Hong Kong.