There were ripples in the sand like the ripples in a sheet of tin roofing. Once, walking through the trees behind her apartment building, she had found a sheet of rippled tin draped across the path beside the tennis courts. Dirt and leaves filled the corrugations, with weeds like bundles of stickpins growing through here and there, all round heads and long thin needles. A year later, the sheet was completely buried by the soil. She was unable to make out even the slightest rib or corner of it. The only sign that it was there at all was the clunking noise a certain section of the path made whenever her foot fell across it. For a moment or two she was there again, in that patch of woods behind her apartment building. It was night, and the headlights of a car entering the parking lot were coasting through the branches of the trees, slipping from limb to limb. First they illuminated one of the oak branches directly over her head, and then they slipped off the edge, leapt thirty feet through the air, and came together again on the bark of a fir tree. There was no difference at all between here and there, or if there was, the lights didn't recognize it.

Then she saw the marbles rolling over the leaves and she blinked and she was back in the dunes. There was a formation of white stone in the distance, knobbed and hunched to one side, one of those tall desert pillars that had been bleached of all its color by the sun. The marbles turned toward it, and she marched along behind them.

Sweat was pouring down her face, down her shoulders and her back, dripping off her fingers and the tips of her breasts. It accumulated at her feet as she walked, an immense clear lagoon reflecting a hundred wiry kinks of sunlight. Eventually the pool spread past its own boundaries and the sweat trickled away, draining slowly into the yellow sand. She watched it disappear.

The wind was at her back, and she felt good, invigorated. She felt as though she could follow the marbles for days without tiring a single muscle. The desert was much cooler at night, and the scorpions and lizards lay for hours on the flat brown rocks that were gradually releasing their heat back into the sky, poised there like statues. When the sun rose, the lizards crawled back into the shadows, but the scorpions barely moved at all. The formation she had set out toward – the pillar of white stone – was actually an arch. It was only the sidelong view that had made her mistake it for a pillar. The marbles crossed beneath the inverted U of the arch and circled around one of the legs to cross under it again, and then again, and then again, like leaves caught in a back current. They were a bright quivering silver in the light of the sun, a color with a thousand worms in it, even the black marble and the green one and the gray one.

It was on their fifth circuit around the leg of the U that she followed them under the arch and through the sliding glass doors of the shopping mall into the parking garage, which was the frozen bay, where a broken mass of ice floes kept tapping their bumpers and sawing past one another with metallic grinding noises.

She hopped over a fissure and continued on. The sand was snow again. The confused noise of the car horns faded away behind her. She wasn't sure how far she had come from her original campsite, but it must have been at least a hundred miles, if not more. She veered with the marbles around an upturned shoulder of sea ice. The snow squeaked beneath her heels.

As far as her eye could see, the bay was a bobbing field of pack ice, interrupted only by the occasional small iceberg. It was jigsawed with bending cracks of ocean water that shone brilliantly in the red light of the sun.

She was close enough to the open water that herds of leopard seals lay sluggishly about on the ice, groaning and whistling and bubbling and grunting. They were calling out to one another or to the universe, she wasn't sure which. Their voices were so animated that she almost believed she could understand them.

Let the fish swim through the traces, one of them said.

Where has the moon gone? Where have the stars? said another.

All worlds are one world, said a third.

And then Laura forgot what she was hearing, and the noise became exactly what it had been before, a din of barking. It was not the sort of barking that could ever be mistaken for the barking of dogs, but that was the thought that came to her mind. She thought in particular of the dogs that used to live in her neighborhood when she was a little girl. She remembered the way that when one of them, any one at all, would start barking – at a delivery truck, say, or a slamming door – all the others would take up the call in an expanding ring of yips and growls that made it seem as if there was nothing in the world but dogs: dogs that chased Frisbees and pawed at the dirt, dogs that charged after you as you rode past on your bicycle, dogs that stood over sprinkler heads on soft green lawns, lapping at the fans of water like puddles suspended in midair. The dogs didn't seem any larger than they had ever been, but it was undoubtedly true that she was weaving her way through their hair as she walked, hitching clumps of fur to the side as she marched over the ice floes.

Which meant that she and the marbles must have become smaller. Why was she always becoming smaller? she wondered. She put her foot down on a lump of ice that was also the ridge of the dog's spine and almost twisted her ankle. She would have to be more careful where she stepped in the future.

The fur along the dog's back, along with the great dented promontory of its head, blocked out most of the landscape. The sunlight came through in glints and flashes that took on the shape of the openings between individual shocks of hair, V-shaped windows that cracked apart for only a few seconds before they swung shut again. Every time she saw the light flickering out of the corner of her eye, she was compelled to jerk her head around. She was like a marionette. She couldn't help herself.

She thought of the blind man who used to stand in the atrium of the Coca-Cola building without a dog or even a cane, listening to the water as it poured down the wall of the fountain. He had jerked his head with the same instinctual twitch whenever something new caught his ear – footsteps approaching across the marble floor, the ding of the elevator coming to a stop beneath the mezzanine, trees rustling in the air-conditioning. He carried an old leather satchel that he used to set down at his feet, where it would spread its lips open like a dying lily, and whenever people dropped their coins inside, he would dismiss them with a wave of his hands, saying, "I didn't ask for that. I'm no beggar," before he emptied the satchel into the wishing pool. He was the kind of person she saw almost every day, then promptly forgot about until she saw him again.

The dog she was riding was not blind, though. It went racing after something it had spotted on the ice. She had to cling to its fur with both her hands to keep from falling over. The marbles trembled and bounced against its tallowy white skin, just visible between the roots of its hair.

Then the dog stopped, hunched over, and wrenched its head to the side as though it had caught a rabbit in its jaws. She slipped down its back and tumbled off onto the ice, landing on her butt.

She picked herself up and brushed the snow from her body, collecting the crystals in her palms and pouring them into the fountain over the thousands of silver coins, which shimmered in the light of the atrium. The still water reflected the scarves and curtains of the aurora. She watched them snap and flicker above the coins. Then she set off down the corridor that connected the atrium to the public relations building. The marbles were still rolling along in formation, though the air in the corridor was dead-motionless, even in the wake of her body, and she could no longer be sure what was driving them forward. Plainly it wasn't the wind.