The sound of these bridges beneath her feet was one she quickly learned to recognize, the hollow thwud of snow with nothing supporting it. She was always frightened that the ground would crumble away while she was trying to walk across. Somehow, though, it never did. Often she would put a leg or a foot through the snow, but she was always able to lift herself back out.
The sledge's flippers were fully extended, and it would slide over the gap on its own as soon as she began pulling again. It was becoming harder and harder, though, for her to draw the sledge at all. The strain of the cold, the twelve or more hours she spent between breakfast and dinner, between one meal and another, the neverending exertion of making her way over the drifts – it was all taking its toll on her. She was feeling weaker every day. Her knees kept buckling, she kept losing her rhythm of breathing.
It was on her fifth day of sledging – her eighth away from the station – that a dense, murky fog settled over the ice. Her flashlight was useless in such conditions, shining back against her hands off the motionless white wall. A small button of moonlight capped the fog, dull and lusterless, but its light was too weak to reach the ground. She wouldn't have seen it at all if she hadn't happened to look directly above her.
She spent hours walking blindly forward, trying to feel the changing shape of the ground through the soles of her boots. Was the shelf rising or dipping? How slick was the snow and how thickly was it packed? Was that the lip of a fissure she felt or simply the falling edge of a furrow? She checked her compass every few minutes to make sure she hadn't wandered too far off course. She tried to keep to a straight line.
She had been pulling for most of the day when a wedge of sky appeared ahead of her. First it was just a cup-shaped hole through which she was able to glimpse a few weak stars, but then the fog parted around it, spreading open as though someone had unfastened a giant zipper, and the moonlight came pouring through. She propelled herself forward with a dozen driving jabs of her poles, hurrying toward the light. The fog dissolved into clear air around her. The weight of the sledge seemed like an unnecessary burden. She would have thrown it off if she could have – just thrown it off and run. She saw the ice that lay above the crevasse, a thin sheet of brittle shining glass, a split second before she was on top of it. But there was no time for her to stop.
She said something out loud – "Wait!" she thought it was, though maybe it was "Shit!" – and then the ice made a splintering noise, shattering into a thousand fragments, and she felt herself falling.
She was caught by the straps of her harness. Her neck wrenched backward, the air rushed out of her lungs, and she heard a clattering sound. She saw white shapes like moths or butterflies floating across her vision in the darkness.
After a few seconds, she began to breathe again. She was dangling inside her harness. She kicked at the air, casting about for a ledge, a foothold, anything. The walls must have been ten feet apart. Her legs kept pinwheeling between them. Whenever she managed to touch one, her feet would slide loose, and she would start swaying back and forth again. Finally she brushed up against what felt like a pressure cleft or an indentation, but before she was able to anchor herself to it, she began sliding down again.
It took her a moment to realize what was happening: the sledge was being pulled toward the fissure. She dropped five feet in a matter of seconds, then halted for a moment, spinning in her harness, before she dropped another two.
She waited until she was sure she had stopped. Then she looked up. The effort of craning her neck made her dizzy, but she forced herself to ignore the feeling. She could see one of the flippers projecting over the edge of the cut. It was outlined against the sky, a stream of stars contained between the solid black walls of the crevasse. The other flipper was not visible to her. The sledge must have lodged against a ridge or a snowdrift, twisting the runners off center. That had to be what was holding it in place. Temporarily.
Delicately, she reached for the wall. She was closer to it now by perhaps a foot. The rope held steady. The ice was hard and slick, with none of the snow that had given her traction when she was making her way across the shelf. She prodded it gently with her mitts. She could not feel any irregularities there. She was afraid that if she moved too suddenly, she would give the sledge enough momentum to skip off whatever obstruction it had lodged against and her weight would pull it into the gap. The walls were too wide for the flippers to be effective, which meant that the sledge would either crush her as it fell or go plummeting past her body and yank her into the void. How deep did the crevasse go? She wouldn't be surprised if it bottomed out at the ocean itself, that thin band of water that had somehow managed to remain liquid beneath the pressure of the ice: barely moving, home to absolutely nothing.
So she could freeze to death, or she could fall and break her neck, or she could drown. Those were the possibilities.
And then there was a fourth possibility, the only other one she could think of. She could climb the rope and lift herself out of the crevasse. She could save herself.
Or not. She had to admit she was tempted to undo the harness and simply let herself drop. It would be a thousand times easier that way. She would never have to pull a sledge again, never have to struggle or wish or remember again. She imagined death as a wonderful melting. The cold would pass out of her blood. She would be so much warmer. No one would ever find her or know what had happened to her, no one would ever see her again, and what difference would it make? The world was over anyway. She would never meet another living soul.
But in the end, she knew, she couldn't let herself do it, couldn't let herself fall. She had to keep struggling, for the same reason everybody else kept struggling, or at least they always had in the past. She felt that to let go of the rope would be cheating.
She looked up again. The nipper was still hanging over the edge of the fissure. She understood that if she was going to make it to the surface, she would have to start now, before she fell asleep and the rest of her strength drained away. She had given herself a fifteen-foot lead on the sledge, so the climb couldn't be any farther than that. She brought her hand to her pocket to put her flashlight away, but realized she was no longer carrying it. She must have dropped it when she fell. She looked between her boots to see if she could spot a pinprick of light twinkling somewhere below her, but there was nothing there to see.
The flashlight was gone. But she couldn't worry about that now.
She tried to take hold of the rope, folding her mitts stiffly around it. They crunched and crackled as the ice inside them snapped loose. At first she thought she had gained a grip on the rope, but as soon as she attempted to lift herself, her hands slipped free. She tried once more, and the same thing happened. Her mitts were too rigid. It was obvious that if she was going to climb out of the crevasse, she would have to use her bare hands. She took her mitts off, stuffing them deep in her pockets. The lining had adhered to her skin, and she had no choice but to leave it in place for now. She took hold of the rope again. Immediately, the tips of her fingers began to sting, as though she had plunged them into a mass of thorns, but within seconds they were numb. She managed to pull herself a few fists higher. Her muscles threatened to burst apart in a hundred limp strings, but the sledge stayed in place. So far, so good. She hoisted herself another few inches and then her strength gave out and she lost her grip again.