Johnny von Neumann was an enigma. As a young man, he stunned those around him with his monomaniacal pursuit of the unshakeable foundations of mathematics. But when his faith in this all-encompassing system crumbled, he began to put his prodigious intellect to use for those in power. As he designed unfathomable computer systems and aided the development of the atomic bomb, his work pushed increasingly into areas that were beyond human comprehension and control – and that threatened human destruction.