A gripping story of mathematics, computers, cryptography, and homosexual persecution. Hodges tells how Turing's revolutionary idea of 1936-- the concept of a universal machine-- laid the foundation for the modern computer. Turing brought the idea to practical realization in 1945 with his electronic design. This work was directly related to Turing's leading role in breaking the German Enigma ciphers during World War II, a scientific triumph that was critical to Allied victory in the Atlantic. Despite his wartime service, Turing was eventually arrested, stripped of his security clearance, and forced to undergo a humiliating treatment program-- all for trying to live honestly in a society that defined homosexuality as a crime.