Four boys and a dog find a hole in 1940. Inside are the horses, the aurochs, the swimming stags. Within fifteen years the visitors’ breath has grown a green bloom across the pigment, and in 1963 the cave is sealed.

Two hundred metres away they build another one. Concrete shell, hand-painted from photogrammetry, correct to the millimetre. It opens in 1983. Everyone you have ever met who has been to Lascaux has been to this.

A third version was built later and sent on tour, so that the cave could visit cities.

The seventeen-thousand-year-old painting is now the only version nobody sees. It has been demoted to a master file. It exists in the mode of a negative in an archive: it authorises the copies and is not itself in circulation.

Note that the first cave was already this. Somebody stood in the dark holding a lamp and painted a horse that was not there — a horse assembled from other horses, at one remove, on a wall, for an audience. The whole apparatus is present at the origin. There is no layer under it where an unmediated person is looking at an unmediated animal.

It is copies all the way down, and the bottom copy is a horse.