Along with Satre, Camus and Orwell, Arthur Koestler helped to shape the ideas of today. Once a communist, he saw through Marxism and led the intellectual counter-attack that culminated in the fall of the Berlin Wall. His writings on science introduced millions to cutting-edge theories of evolution and the workings of the human mind. His speculations on human nature and the future of mankind in the atomic age stamped a generation that grew up in the shadow of the Bomb. As restless in his personal relationships as he was in politics, his violent affairs with women were legendary. His fascinating study is t he first to make use of Koestler's private papers and draws on previously secret documents held by the KGB and the FBI, exposing the depth of his involvement in the Communist Party and, later, his relations with the CIA. It also reveals the darker side to his nature, which led to the tragic dual suicide with his third wife, Cynthia, in 1983. David Cesarani has ensured Koestler's place in the pantheon of intellectual giants of the twentieth century as surely as the 'warts and all' approach is guaranteed to perpetuate the controversy that swirled around Koestler in his life and death.