As we sweep the walls with our lanterns, a line of aurochs and horses, stags, bulls, and a bear appears out of the darkness, painted onto the stone with such confidence and elegance the animals appear to be alive, moving even. At the end of the large chamber, there are two passageways, one leading left and the other right. We choose the left. It is longer than the first chamber, but much narrower, and we find a dizzying array of figures—a huge black bull, a cow, more horses, more aurochs, more bulls, bison, ibexes, and a magnificent black bull that I estimate is about thirty feet long.

“I am gobsmacked,” Élodie whispers, her voice full of reverence. “This is the deepest memory of my people, my ancestors. It’s as if we are walking through their brains, or their souls!”