The history of the computer is entwinedwith that of the modern world and with the life of one man, the brilliant buttroubled Alan Turing.How did the computer come to structureand dominate our lives so totally? In Jon Agar's enlightening story of the'universal machine', we discover how Turing's groundbreaking work not onlyhelped break German codes during the Second World War but also founded the beginningsof the modern computer.Persecuted by the authorities for hishomosexuality, and ultimately hounded to suicide, Turing's personaltribulations are as relevant to the modern world as his work on computing, asindicated by his posthumous royal pardon of 2013 and the recent film The Imitation Game, which focuses onTuring's turbulent life.