They were, after all, alone on the Moon, the only living creatures on a planet.

She said, “You feel horny, don’t you?”

He grunted. “I haven’t felt so horny since my father’s funeral. But—”

“But it wouldn’t be wise,” she said.

“Damn right it wouldn’t,” he said; and when he looked into her eyes, he saw they both meant it.

They stepped apart. She began to cast around, in the piles of equipment loosely stacked on the floor.

“What are you looking for?”

“A weight.”

“What for?”

“A plumb line. If we can’t tell which way is up we need an attitude reference. We don’t have an eight-ball in here.”

She dug out one of Henry’s smaller geology hammers, and tied a piece of string to it. When she hung it up from a loop in the roof of the shelter, it hung straight down.

“So we aren’t tipping,” Henry said.

“No. That damn thing knows which way is up, even if we can’t tell.”

“Yeah.”

She reached up and, with an easy low-G bound, pulled herself up into her hammock once more. “Good night, Henry.”

“Yeah.” He clambered back into his own hammock, and pulled his sleeping bag up around his neck.

He tried to settle his mind.

He listened to Geena’s soft, even breath. When he thought he was tipping, he looked up, and he could see the hammer dangling there, calm and rational, a link to a world where the laws of physics continued to work.

He closed his eyes, determined to sleep.

To his surprise, he succeeded.

2

Alone in lunar orbit, Arkady set his alarm to wake him during a period when he was on the far side of the Moon: invisible to all mankind, to remote blue Earth, even to the two humans scrambling through the Moon dirt near Aristarchus, here he could enjoy the ultimate privacy.

He lay for a moment in his sleeping bag. He was surrounded by equipment, bags and containers and documents, fixed to every square centimetre of wall surface. It was like being in the middle of a busy railroad station, he mused, luggage scattered everywhere.

The craft’s noise was a miniature orchestra: the whirring of different electrical devices, fans, regenerators, carbon dioxide absorbers and dust filters, gadgets which were never switched off. The noise rattled around him, echoing in this compact metal barrel. It was, he supposed, about as noisy as a busy apartment — with one difference: these were only mechanical sounds; there were no human voices here, save his own.

Once, for an experiment, on the far side of the Moon, he’d turned everything off. Just for a moment. The silence was oppressive: in his ears there was only the susurrus of his own breath, his rushing blood, and beyond that a stillness that stretched a quarter-million miles. It gave him an unwelcome sense of perspective: noise seemed to make the universe more friendly.

Loose objects — pens, paper, food wrappers — swam through the air past his head. They moved languidly in the gentle air currents from the fans, sometimes darting this way and that in the random flow of the air, like improbable fish.

Here, everything floated: dust, pieces of trash, food crumbs, juice drops, coffee, tea. None of it would settle out, and all of it ended up suspended in the air. This enhanced Soyuz was fitted with a jury-rigged air circulation system, and a lot of stuff would end up collected on the intake grille of fan ducts, which he kept covered with cheese cloth. Once a day, he would wrap up the cheese cloth with its assorted trash and replace it with a fresh one.

Most things, if he lost them, ended up on the grille. If he needed something in a hurry he had a little rubber balloon that he kept in his coverall pocket. If he blew this up and released it, it would drift with the prevailing air currents and he could just follow where it went.

If he was thinking about chores, it was time to get up.

He clambered out of his sleeping bag. He started his day with bread, salt and water.

He spent some time cleaning up the Soyuz.

He had some napkins soaked with katamine, a scouring detergent. He wiped down the wall panels, the hand-rails, the door hatches, the control panel surfaces, the crew couches. And, with a little hand-held vacuum, he cleaned all the tough places where dirt built up. He opened up wall panels so he could vacuum the bundles of pipes, cables, fan grilles and heat-exchanger ducts there. When he did that he found a pen he’d lost right after the launch; he tucked it in his pocket, unreasonably pleased at this little triumph.

He had grown used to life in microgravity.

When he’d first arrived on Mir, he remembered, he could barely move a metre without catching his feet on side panels and banging his legs on anything fixed there: documents, cameras, lenses, control panels. Now he could fly through hatches and compartments, wriggling like some lanky fish, neatly avoiding the equipment and obstructions. If he had to cross some space without handholds, he had learned how hard he had to push. When he had to maintain a position at some work station, he had learned to find a post around which to wrap his legs, or else he would find somewhere to lodge his elbows, feet, knees or even his head, thus holding himself steady; sometimes he would use his legs as clamps, to hold maps or other documentation.

He had come to depend heavily on the advice and experience of other cosmonauts who, for nearly thirty years now, had been learning to survive long-duration assignments in space.

There had been that time, for instance, when the Progress resupply ship was late and he and his crewmates had been reduced to burning lithium perchlorate candles to sustain their oxygen. And then the recycling plant that connected to the toilet had failed, and the sewage tanks had filled up. The crew had been forced to open up the tanks and simply stir the sewage, to reduce the volume. That had worked, but the stench had been awful and did not seem to dissipate, as the days wore on; after all, they could not open a window up there to let in fresh air.

Still, there had been some comedy as their American guest, brought up there in air-conditioned comfort on Shuttle, had tried to cope with all this; she had looked on with horror as the sewage tank was opened, antiseptic wipes over her face to protect her from week-old Russian shit — or, as she had comically put it, “human post-nutritive substance’…

There were two e-mails for him today, transferred up via Houston to the IBM laptop fixed to one wall by Velcro patches. The first mail was relayed from Korolyov. It seemed his coefficient of errors was up to point three five, an unacceptably high level by historic standards.

Arkady sighed and discarded the mail. It was a peculiarity of the Russian system — seen by Geena’s American eyes at least — that every error he made, on this or any other mission, was recorded by his controllers on the ground. Basically, after a mission, he was evaluated not by what he did or how much he accomplished, but by how many mistakes he made.

If he saved the world, he thought wryly, maybe they would overlook his unsatisfactory error ratio.

The second mail was more pleasing. It was from workers at the Krasnoyarsk Hydroelectric Power Station in Siberia. One summer, as a student of the Moscow Institute of Aviation, Arkady had worked at Krasnoyarsk on a dam construction project.

› To celebrate the first Russian lunar flight, by the joint decision of the workers and the MIA student construction workers in Sayany, Arkady Berezovoy is nominated as an Honorary Concrete Worker in Dmitri Syroyezkho’s work team. His salary will be transferred to the Russian Peace Foundation. We wish you Siberian health, happiness, successful completion of your mission, and a safe return to Earth. We embrace you as a friend. Come and visit us in Sayany…

Arkady was moved. He was sorry Geena was not here to see this — though he was glad her American ex-husband Henry was not here to mock. Americans would never understand such a gesture as this, and would deride it.