Queen Victoria died on 22 January 1901. Do you know what day of the week that was? David Kidd does - in fact he'll tell you (as fast as a mini-computer) that it was Tuesday - like 12 March 1996 and even 1 March 2044. But ask him to add eight and seven, and the chances are he'll get it wrong. How come? Because he has an astonishingly low IQ of 65. Like David, Noel Patterson and Stephen Wiltshire are also classified as severely mentally impaired. Yet their musical talent and artistic ability respectively, impressed Antony Hopkins and Sir Hugh Casson. Q.E.D. explores a bizarre psychological phenomenon - Idiots Savants to the 19th-century Frenchman who first identified it - in English 'the foolish wise ones'.