6.30am – satnav bright in the rainy dark – to Stansted Airport, our lanes clear, but incessant headlight stream swarming in to London. Imagine that your job requires you to drive into London every day at 6am; perhaps it does. Stansted Airport: modern world writ large. Huge steel beams frame World of Mammon, thousands of shelves of exquisitely-displayed perfumes clothes phones phone accessories spirits wine scarves ties food… high-gloss images of airbrushed perfect people buyingshoppinglivinglifetothefull: don’t you wish you were? Instead of fretting about the luggage restrictions of Ryanair (1 bag under 10Kg in the cabin – otherwise an extra £25 each way).

The American is dabbing the little wound on his bald head: he was warned about the low roof and the stalactites but immediately walked into one. The cave, though immaculate, still has that deep rich old smell, beyond time. Above us two reindeer are nose-to-nose, painted onto the rock shelf. The standing deer seems to be licking the other’s snout, standing over it, sympathetically, or triumphantly – who knows? A herd of bison stampedes around the walls at head height; the undulating surface of the walls would give body and movement to their forms, especially when lit from below by flame. 17,000 years ago artists were painting these living animals in manganese onto the wall, and they still live.