The process of codebreaking is very similar to that involved in solving puzzles. This collection offers the codebreaking entusiast a tough, but enjoyable, challlenge, with puzzles divided into three levels of increasing difficulty. The final level is intended for the expert, fittingly for a book entitled 'The Turing Tests'. Alan Turing is known as the father of modern computing and for his work at Bletchley Park in solving one of the most strategically important puzzles of World War II, the Enigma cipher.