The visitors were still here. A tech opened a cylindrical case inside a glove box, and pulled out a Moon rock: small, fist-sized, nondescript, sawn in half. Geena could see the vertical burns of the saw. The visitor had his picture taken with it, his grinning face outside the glass, the rock held by a black-gloved hand inside the glass, the camera angled so as to avoid the flash’s reflection from the glass.

And in the sterile light of the lab, the ancient rocks from the Moon — many of them older by a billion years than any rock that had survived on Earth — sat, wizened and lumpy and wilfully irregular, like resentful old men in a rest home.

3

Monica Beus was with Alfred Synge, on the Hawaiian island of Oahu.

She emerged from the dark crater into the blinding light of the sun. She pulled on her sunglasses and checked her floppy hat. She’d snapped Alfred’s head off when he showed up with this big hat for her. For the sun, he said. But he was right, of course; the chemotherapy had left her so bald her scalp would fry like an egg, and she was too damned stubborn, naturally, to wear a wig.

So be it. She wore the damn hat, and forgave Alfred for his residual love for her.

Breathing hard from the climb, she clambered on top of an old gun emplacement with a bunch of other tourists and studied the view.

She was at the highest part of Diamond Head crater, here on Oahu. She was surrounded on three sides by Pacific Ocean. The water was royal blue, laced with whitecaps, in its beauty showing no signs of the problems Venus had brought: the plankton die-backs, the collapse of the food chain in some parts of the oceans, depletion of stocks of fish and mammals. In the south she could see windsurfers skimming over the waves, radiation-proof skinsuits gleaming, their elegance and speed a balance between forces, aerodynamic and gravitational. In the west, the sun was already dropping towards the horizon. To the north the Miracle Mile along Waikiki Beach was a thin, golden strip of sand walled off from the interior by slab-like high-rise hotels. Sun, sand, sea, tourists.

And when she looked back she could see into the crater of a volcano two million years dead.

They found a seat. Alfred dug under his poncho and pulled out a laptop; without preamble, he started showing her images of Venus.

“Before and after,” he said drily. He retrieved a classic Venus-from-space image, the featureless pool ball. “Venus was our neighbour,” he said. “At its closest, only a hundred times as far away as the Moon. And it wasn’t so different from Earth in size. But that’s as good as it gets. Otherwise, it was a hell-hole. Fifty miles of carbon dioxide, laced with a little sulphuric acid. So hot the rocks glowed, dull orange.”