Less than 50,000 years ago mankind had no art, no religion, no sophisticated symbolism, no innovative thinking. Then, in a dramatic and electrifying change, described by scientists as "the greatest riddle in human history", all the skills and qualities that we value most highly in ourselves appeared already fully formed, as though bestowed on us by hidden powers. Graham Hancock sets out to investigate this mysterious "before-and-after moment" and to discover the truth about the influences that gave birth to the modern human mind. His quest takes him on a journey of adventure from the stunningly beautiful painted caves of prehistoric France, Spain and Italy to remote rock shelters in the mountains of South Africa where he finds a treasure trove of extraordinary Stone Age art, ending in the depths of the Amazon rainforest, where he drinks the powerful plant hallucinogen Ayahuasca with Indian shamans, whose paintings contain images of "supernatural beings" identical to the animal-human hybrids depicted in prehistoric caves and rock shelters. Could these "supernaturals" be the ancient teachers of mankind? And is human evolution in fact more purposeful and intelligent that we have barely even begun to understand?