Just above him, Geena barely made a dent in her own hammock, but he could see the curve of her hips, the way she’d tucked her legs up a little way towards her stomach, just like she always used to.

He tried to sleep.

The shelter was full of noise, the bangs and whirs of coolant pumps and ventilation machinery.

He’d read that the old Apollo guys had trained for sleeping on the Moon by camping out in Lunar Module simulators, with a tape of LM noises playing in the background. They should have just slept in a boiler room, he thought.

…There was a creak. He had a sense of falling.

His eyes snapped open.

“Geena,” he hissed. “Are you awake?”

Geena’s voice was hushed. “Hell, yes, I’m awake.”

“Did you hear that?”

“Hell, yes, I heard it.”

“Do you think we’re tipping?”

“I don’t know.”

“You don’t suppose this damn thing is going to roll over altogether?”

“Can’t you tell?”

“No. I can’t tell for sure which way is up. This low gravity—”

“Henry.”

“What?”

“Why are we whispering?”

Henry pushed his way out of his hammock. He collided softly with Geena, who came tumbling down from the top bunk; he held onto her upper arms, to keep them both from falling over.

For a moment they stood there like that, in the milky gloom of the shelter. Geena’s face was only a few inches from his, outlined by the subdued stand-by lighting. Her eyes were pools of darkness, her mouth a shadow. But her breath was warm on his face, the heat of her flesh in his hands tangible; for the first time he realized how deeply, utterly cold he had felt, how much he needed to be held by another human being.

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.