The film traces the atypical career of Gilles Clément, gardener and landscape architect, but also writer. Marked by ecology, he questioned the art of gardens at the end of the twentieth century, with the garden in motion, the planetary garden or the third landscape. From its secret garden, the "Valley", lost in the woods, in the Creuse, we discover the main achievements that have marked its creation, such as the Domaine du Rayol in the Var, Henri Matisse Park in Lille or the third garden landscape on the former military base of Saint-Nazaire. The garden is not just a square of potatoes, it is a place where political utopias are practiced, where scientific thought is practiced and where dreams take us to other worlds.