The gumbo glistened before her, like a plain of dried blood, unmarked and without frontier.

It wasn’t like a dawn on Earth.

As the light came up, there was no sense of opening out, of liberation from the confines of the night. The horizon was so close by, just a couple of miles, and obscured anyhow by the murky mist and haze. And the sky overhead, even on a cloudless day, was a lid, complete and orange and seamless. It was like being in a box: orange haze above, purple-black slush below, bound in by a horizon as close as a fence. And as she walked, bringing nothing but more miles of tholin slush into view — no roads, no trees, no gas stations — she became oppressed, trapped by the lifeless murk.

Benacerraf started to develop sharp twinges in her shoulder muscles, and shooting pains in her shoulder blades. And besides, her right foot was beginning to feel cold and raw. Forward motion was only possible with sharp tugs at her load; she could feel the pressure points in her shoulders, waist, knees and feet.

She stopped, trying to work the stiffness out of her shoulders, but confined in her movements by the heavy suit. The pressure of the harness bands on her chest and gut receded, briefly; she could feel bruises gathering, and burns about her hips where the harness was too tight.

She dropped her head, and ploughed forward again, yanking the sled away from the cloying gumbo.

They spoke rarely.

Mostly, she was alone with the rasp of her breathing, the high-frequency whir of the fans in her backpack and the hiss of oxygen across her face.

She tried to dull out her thoughts, not to think about what lay ahead of her and behind her, how every step was taking her further from Discovery. She concentrated, for instance, on the familiar noises of her suit; she tried to imagine she was in space again, in low orbit above the glowing, beautiful Earth, and that the suit was a bubble of warmth and comfort around her.

But the pain broke through that too easily, from her sore foot, her hands, her shoulders.

She tried not to think about the silence on the comms links.

The extinction of mankind.Rosenberg, figuring from what he knew of the parameters of the rock the Chinese had dropped, said there could be little possibility of human survival. It was the K-T boundary event over again, he said.

What proportion of “mankind” could she have met during her life? A few thousand? And how many did she care about?

Three people, she thought. Just three. And now she couldn’t even find out if they were dead or alive.

Way to go, Paula.

Later, she got angry.

She got mad at her balky sled, every time it stuck in some particularly viscous patch of gumbo and dragged her backwards, yanking at all her sore points. She got mad at the dull Titan weather, at the winds that chilled her but failed to freeze the gumbo to a useful surface.

She got mad at Rosenberg. That wasn’t hard.

She could sink inside herself and pick over some aspect of Rosenberg — the things he said, the body stink when he opened up his suit — and chew on it inside her head for hours, she found, building up the irritation to a near-hatred. Even those CELSS farm baby carrots, too bitter for her to eat, which he religiously devoured, insisting they were good for oxygen deficiency.

She could plod like this, steadily hating Rosenberg, and then, when she looked at her astronaut’s Rolex, she’d find — if she was lucky — that maybe an hour had passed, bringing her that much closer to the moment she could stop.

After a time, though, even the anger didn’t work. There was too little stimulation for her mind, in the dull landscape of gumbo and haze; she was turned inward, her thoughts stale and repetitive, churning and festering, with no external distraction to relieve her.

Sometimes she wanted to howl, to raise her face to the orange sky and just scream like a frustrated ape. But she knew she couldn’t. If she did, it would let out the beast at last, the Bill Angel craziness she suspected lay deep within her. She would lose her ability to manage this, once and for all.

So she plodded on, muttering. Stick it. Stick it. Stick it. Until the urge to howl dissipated, and the blackness receded a little.

After five hours, they had completed six miles. Benacerraf was exhausted, the little water spigots in her helmet running dry, the air circulating in her suit stale.

Rosenberg pulled alongside her. He ran a gloved finger over her bandolier. “Look at this,” he said, and he lifted up a harness joint with a fingertip. The stitching was torn, and Benacerraf’s harness was twisted. “This joint is double-stitched, but these couch harnesses were never designed for the kind of stresses we’re subjecting them to now. I guess you didn’t notice. You’ve been dragging the sled with the harness out of alignment. Your torso must have been twisted. No wonder your shoulders hurt.”

“Rosenberg, I’m done. Let’s get the tent up.”

“We haven’t completed the schedule, Paula. Another three or four miles and—”

“I know about the schedule. I don’t care about the damn schedule, Rosenberg. I’m telling you I need a break.”

“It’s just that right now we’re in as good a position as we’re going to be. We’re still full of food, and our core body temperatures are high, and we’ve had plenty of reasonably natural sleep back in the hab module. Later, it’s going to be harder to—”

“Help me raise the fucking tent, Rosenberg, or you’re going to get a sled runner up your ass.” She pulled the parachute fabric off her sled.

Still complaining, he helped her haul out the tent.

The skimmer tent was a ball eight feet across. The airtight skin was reinforced with parachute canvas, to give it additional strength. Rosenberg roughly inflated it with a feed from oxygen and nitrogen tanks. They anchored it to the gumbo with ropes and wide, flat, anchor-like spikes, driven deep into the slush. The tent sat on the slushy surface of Titan like a sad beachball, its muddy yellow surface drab and uninspiring, fat air and power lines snaking into it from the tanks in Rosenberg’s sled.

Now the two of them worked with the snow shovels to cover the tent over with a thick layer of slush. This ought to retain some of their heat. It was slow work; the slush at first just slithered off the canvas, and it took long, hard minutes of labor before the tent was covered over.

Rosenberg led the way into the tent, crawling through the crude airlock. Benacerraf followed. In her bulky suit, she kept colliding with Rosenberg’s limbs and helmet; she felt like some bug crawling around inside a cocoon.

Rosenberg hooked up a low-watt light and an electric heater. “Wait a few minutes until we warm up.”

The elements of the heater started to glow crimson red, a sharp color very unlike Titan’s dull orange. She sat close to the heater, watching the elements grow brighter, seeing their multiple reflections from the layered visors of her helmet. It was, she thought, heat brought to this ice moon from the remote center of the Solar System.

Rosenberg spent the time fiddling with the spare PLSS. This backpack — intended for Nicola Mott — had been rigged with a powerful vacuum pump and blower. They would use it to keep the tent air circulating through its lith hydroxide carbon dioxide scrubbers. If either of their packs failed during the march, this spare would serve as a backup.

At last, Rosenberg said the air and temperatures were okay.

Benacerraf cracked the seal of her helmet.

Chill air gushed into her helmet, at her neck and over her face. Her breath immediately misted before her face, and gathered as frost on the glass of her faceplate. She coughed, and took a deep breath. The air was so cold she could feel it burning at her lungs, and digging into the flesh of her face. The warmth of her suit seemed to gush out at her neck, and the cold seeped deeper into her.