One of the great mysteries of human history is why humankind, which evolved anatomically millions of years ago, suddenly at around 50,000 BC first began to think symbolically, as we see from Stone Age art. In order to investigate this mystery, Graham Hancock journeys first to explore the wonderful cave paintings of Southern France. There he learns the theory of an unorthodox anthropologist that the distinctive features of these paintings and the similar paintings created by tribesmen in South America show them to be representations of the successive stages of trance states induced by psychoactive plants. Could it be that the most dramatic evolution in human consciousness was the result of experimentation with drugs? Hancock then goes to live with one of these present day tribes in South America, in order to experiment with psychoactive plants, enter trance states and meet the gods of the tribal elders. At the end of this dangerous experiment, Hancock does indeed encounter the gods of the tribal elders and begins to see in their lineaments the familiar shapes of the founder gods of Egypt about whom he has written so much. Hancock's historical search shows that in all places and at all times these same entities seem to have appeared to people in this drug-induced trance state. Hancock asks the question, could it be that rather than being mere hallucinations, these entities exist in a parallel dimension, sometimes squeezing through into our own dimension in order to direct the course of human history? Graham Hancock's new book is a groundbreaking new case for the reality of the supernatural. It is in a sense a return to the extremely vivid first person detective story of Hancock's first bestseller The Sign and the Seal. The account of his journeys both real and 'inner' are utterly enthralling.