Like many in the community of theoretical physics, Professor Hawking is seeking to uncover the grail of science - the elusive Theory of Everything that lies at the heart of the cosmos. In his accessable and often playful style, he guides us on his search to uncover the secrets of the universe - from supergravity to supersymmetry, from quantum theory to M-theory, from holography to duality. And he lets us behind the scenes of one of his most exciting intellectual adventures as he seeks "to combine Einstein's General Theory of Relativity and Richard Feynman's idea of multiple histories into one complete unified theory that will describe everything that happens in the universe."