At what point in our evolution did we start talking? To paint, play music and travel? When did we build our first imaginary worlds? When was the need to believe born? In short, where, when and how did the contours of man's essence take shape? Going back to the origins of language, art and writing, this documentary by Emmanuel Leconte and Franck Guérin traces the fantastic cultural epic of thought. Although animals also dream, today only our species has the power to recount its dreams, transforming them into stories, narratives and destinies... But where does this astonishing human faculty come from?