She found she was wearing some kind of booties, welded onto the suit, as clear as the rest of the coverall. When she lifted up her foot she could see there was no grip on the sole, no ridging, but she seemed to be able to keep her footing nevertheless.

The ground was a sandy, crusty, rust-brown soil; it crunched when her weight settled on it. There were stunted trees — they looked like willow, or birch — scattered over the plain; none of them came much higher than her shoulder. Between the trees, grass grew. Near her feet there was a splash of flowers, almost white despite the ruddy light, the petals as big as her palm. She knelt down and pulled up a handful of grass. She rubbed the blades between her thumb and forefinger; there was a sharp herbal aroma.

Rosenberg lifted up what looked like a mushroom, a huge puff-ball a foot across. “Mosses, lichens. It’s hard to see in this red light, but I’ll bet these things are livid green.”

“Chlorophyll?”

“Of course these aren’t true plants. They’re just organisms descended from some root stock, which have radiated to fill the various ecological niches…”

She dug up a little of her anger. “Radiated from what? What are you talking about? You’re so full of shit, Rosenberg.”

He said irritably, “Radiated from whatever terrestrial-biosphere samples the ammonos managed to retrieve from our bodies, or the ruins of our base, or the seeds you planted.”

“Ammonos?”

“I told you we had to take this one step at a time.”

She looked at Rosenberg. “You know,” she said, “I’m hungry. And thirsty. Shit. They had no right.”

“What?”

“To bring me back.”

“Yeah. Well, they did it. And I’m hungry too.” He shrugged. “Try anything. We’ve no way of knowing what’s toxic, even lethal… We have to trust the design.”

“You mean you don’t know?”

“Just try something, Paula.”

Near her legs grew a couple of the mushroom-like puffballs, some sparse grass, and a scratchy growth like bruised-purple heather. At random, she dug her hand into a puffball. It imploded, like a meringue, and a cloud of some kind of spores blew up around her arm, clinging to her flesh and the suit. She came away with a handful of the mushroom’s meat. It was white, soft, cold, slightly moist. She suppressed a shudder; the feel of it was repellent.

She lifted it to her mouth, bit off a chunk, and chewed deliberately.

It crumbled, collapsing to a hard residue, like bad sponge cake. It was still cold, and there was the faintest of flavours, an aftertaste of decay.

She swallowed the residue.

Rosenberg watched her intently. “Well, you haven’t choked, thrown up or keeled over.”

“But I’m even more thirsty.”

“Come on,” he said. “I think the ground dips down a little over that way; maybe we’ll find some fresh water.”

They began to walk, parallel to the looming grey-white cliffs.

They came to a stream.

It ran sluggishly through a shallow gully, eroded into the ground. The water was running away from the direction of the grey cliffs, Benacerraf noticed. It looked a little muddy, and dirty grey ice clung to its banks.

Rosenberg squatted and dipped a hand into the stream. He pulled it back quickly, but he brought up a little water cupped in his hands. “Ouch. Cold as all hell. I guess it’s glacier melt, running off those cliffs.” He stared dubiously into the little puddle he cradled. “Drink it, Rosenberg.”

He sighed. He lifted up his hand to his mouth, and sucked in the water noisily. He grimaced. “A little salty. It’s okay. So cold, though.”

She knelt down beside him, and began scooping up water. It splashed over her face, the cold stinging; and she could feel its icy passage down her neck and into her stomach.

Rosenberg said, “These suits seem to keep us warm enough. But drinking this stuff will bring our core temperatures down. We need to find a way to build a fire.”

“Those trees look as if they will burn.”

“We don’t have any way of lighting the fire.”

“Didn’t you ever go camping, Rosenberg…? No, I guess you wouldn’t. You take a couple of sharpened sticks, and—”

He held up his hands. “I believe you. Show me later. Just don’t lecture me about it.” He plucked at the chest-cover of his transparent suit. “I got a more urgent problem. I need to pee.” He clawed at the plastic-like sheet over his genitals, comically.

She realized that the cold water had run straight through her, too; soon she would face the same urgency as Rosenberg.

What were they supposed to do? Just let go, and walk around sloshing? Suddenly her suit seemed constricting, even claustrophobic.

She stood with Rosenberg, and experimented with his suit, pulling the clear material this way and that. At last, she found that if she pinched both sides of the suit’s neck, a seam opened up. Once the split began, it ran quickly along the lines of Rosenberg’s body, over his arms, down his hips and the sides of his legs.

Gently, Benacerraf pulled at the neck, and the front of the suit just peeled away from Rosenberg, like a parting chrysalis.

When the suit lay in a clear puddle at Rosenberg’s feet, he clutched his arms over his chest. “Christ, that’s cold.”

“Don’t be a baby, Rosenberg.”

He walked away, hopping gingerly over the icy ground on the balls of his feet. He moved behind one of the trees, and in a couple of seconds Benacerraf heard the heavy splash of urine drops against the soil, and saw wisps of steam rising around Rosenberg’s legs.

To get Rosenberg back into the suit, they found the easiest way was to lie him down, inside the back section. Benacerraf lifted the front over him and ran her pinched thumb and forefinger up over the opened seal; the material melded together seamlessly.

After that, she took her turn. Oddly, she felt naked out of the suit, even though it had been all but transparent. The ground was hard and icy under her bare feet as she squatted.

So here she was, eating and drinking and pissing and talking, life going on, just as if nothing had happened, as if the world hadn’t ended, as if she hadn’t died and been dug out of the ice and… hell, all of it.

It had never struck her before how much of her time, her conscious attention, was taken up just with the business of being human.

She rejoined Rosenberg, who stood by the stream. They looked at each other.

“Where are we, Rosenberg? Is this Mars?”

He looked confused. “No. Not Mars. Of course not. Mars is gone. This is Titan. Don’t you get it? You’re still on Titan, Paula.” He glanced up at the wide, flawed face of the sun, which filled the dome of heaven above.

Something connected in her mind. Cosmology lectures. Carl Sagan. “If this is Titan—” Oh, shit. “A red giant,” she said. “The sun’s become a red giant.”

He laughed brutally. “You figured it out. Just like I had to. Sorry there aren’t any comforting answers. We might be ten billion years from home, Paula.”

The ruined sun seemed to hang over her head, huge and heavy, as if it might crush her; she wanted to escape from it, run under a tree, hide her head with her hands. “Tell me what’s happened to us, Rosenberg.”

His face hardened further. “You want the short version? You died. So did I. We all died. We were frozen into the gumbo. Later — a lot later — aboriginal life forms dug us out and restored us. Quite a feat.” His voice was thin, trembling.

“We’re stranded here. Is that what you’re saying, Rosenberg?”

Again he looked confused. “Stranded? Of course we’re stranded. Who do you think I am, H.G. Wells?”

She felt a snap of irritation. “Lighten up, Rosenberg. I’m just finding all this a little hard to handle.”

“What the hell do you expect me to say? I woke up ahead of you, that’s all. This is as hard for me as for you. And I’m stuck here too.”

“No way home, huh.”

He frowned. “Paula, Titan is our home now. For the rest of our lives.”