On 29 June, 1982, a man called John Blake appeared mysteriously bidding in the major auction houses of London and New York. He was in reality the 'Sunday Times' journalist Peter Watson. 'The Caravaggio Conspiracy' is a true story of a remarkable collaboration between dealers, auction houses and the law to transform Peter Watson, an ignorant outsider, into an international art dealer. Tonight, Arena, with the help of the participants, traces the story of how Watson, with a fake limp straight from the pages of a thriller, and a potted knowledge from books of art history, conned his way into a world of mafiosi and art dealers and recovered two masterpieces of stolen Renaissance art.