Charles Darwin, the father of evolution and recently voted the man of the last millennium, was chronically ill for most of his adult life. Was his fatal illness, as convention tells us, brought on by his own neuroses? Was this great man of science really a neurotic basketcase fit for the Victorian madhouse? Or was he instead the unwitting victim of an appalling disease caused by an insidious tropical parasite, which he acquired during the voyage of the Beagle? Dr Rob McCall believes Darwin was struck down by a South American 'assassin bug' - carrying a disease that today infects millions of people. He sets out to solve the riddle, but it will take police forensics and the latest medical knowledge to get even close to an answer.