The Shell Line

Part One · Too Tight

Tansy had lived in the same periwinkle shell since the spring, and by the end of August it no longer fit. She could feel it every time a wave came through the pool. A hermit crab in a proper shell can pull in until nothing shows but the tips of her claws, folded across the opening like a door. Tansy pulled in as far as she could, and the soft pink curl of her tail still stuck out at the back, where anything with a beak could notice it, and the shell had not shrunk. She had grown. That was how it went with hermit crabs, and in all the history of the beach, nobody had found a way around it.

The pool where she lived was a long crack in the rocks, filled twice a day by the tide and abandoned twice a day when the water drew back. It held a red anemone, some periwinkles grazing on the weed, two grumpy shore crabs, and nine hermit crabs of different sizes, each one living in a shell that some snail had made and then given up. That was the whole problem. Hermit crabs cannot make shells. They can only find them, and every good shell on the beach already had somebody inside it, and the sky above the pool had a problem too, and it was white, and it screamed. Gulls flew over every day, looking down with one cold, hungry eye.

The biggest crab in the pool was Boone, who lived in a whelk shell the color of wet sand and moved through the weed like a slow barge. Below him came a crab in a dog whelk, then two in top shells, then Tansy, and below Tansy came the small ones, down to Fig, who was hardly bigger than a pea and carried her tiny shell like a hat. Fig had admired Tansy's periwinkle all summer. Tansy knew this because Fig mentioned it constantly. "Lovely shell," Fig would say, drifting past. "Nice and roomy. Shame if you ever wanted to give it away." It was the kind of hint that is not really a hint, because it is not even trying to hide.

There was one empty shell in the pool, and it belonged to nobody because nobody could use it. It was a whelk nearly twice the size of Boone's, lying on its side at the sandy end, thick and heavy and streaked with purple, and Tansy had stared at it every day since July. One evening, with her tail aching from a day of sticking out, she decided that staring was no longer enough. She backed out of her periwinkle, which took real courage, because for the length of a breath a hermit crab with no shell is the softest, tastiest-looking thing on the beach, and she slid herself into the purple whelk.

It was like moving into a palace. She could pull in so far that the light vanished and the sea sounded a long way off, and for a moment she felt like the safest crab alive. Then she tried to walk, and the whelk did not move. It was so heavy that every step was a heave and a groan, and when the first wave of the evening tide came through the crack, it simply lifted the shell, flipped it over, and set it down on top of her. She lay upside down with her legs spinning in the water like a beetle on a bad day, until the wave drew back and she could wriggle out. Above her, one gull circled lower and looked interested.

Part Two · The Line

Tansy fled back into her periwinkle with her pride somewhere behind her in the sand. Boone, watching from his ledge, remarked that a shell could be too big as well as too small, and that a crab who could not lift her house was a crab waiting to be a snack. Tansy had worked that out for herself, but she did not say so. Fig arrived, looked at the purple whelk, looked at Tansy, and asked with enormous delicacy whether the periwinkle might be available now, and Tansy said that it was not. She had nowhere else to go.

The storm came three nights later, a long roaring sea that filled the crack to the brim and left it strewn with weed and broken shell. In the morning, in the sandy end beside the purple whelk, there lay a second shell, a moon snail, smooth and round and perfect, with the snail long gone, and it was not enormous. It was, Tansy judged, running her claw around the opening, exactly the size of Boone. That meant it was useless to her. It also meant she could not take her eyes off it, because of what might happen next.

By the middle of the morning five crabs had gathered around the moon snail shell, and none of them was doing anything. That was the strange part. Nobody tried it on. Nobody fought for it. Boone sat at one side, the two top shell crabs sat at the other, and Tansy and the dog whelk crab waited between them, turning the shell over now and then and settling again. Fig, who had come to watch, asked what everybody was waiting for, and Tansy realized that she did not know. She had seen crabs fight over shells, and she had never seen them wait.

The answer arrived in pieces. The moon snail fit Boone. If Boone took it, his whelk would be empty, and his whelk fit the dog whelk crab, and her shell fit the first top shell crab, and so on down the line, with each crab moving up one house. At the end of the line stood Tansy, who would get the second top shell, a size she had been dreaming about since July. Nobody could move until Boone moved. And Boone was not moving because he was not certain, since a crab who leaves a good shell and finds the new one wrong has nowhere to go back to. Everybody was waiting on one very slow decision.

Tansy looked at the crabs standing about in no particular order and understood something else. If Boone did move, there would be a scramble, and in a scramble the shells went to whoever was closest, not to whoever fit. There was a better way, and it involved standing in a line, and she walked to the empty spot behind the dog whelk crab and settled there with her claws folded. When Fig asked what she was doing, she said she was being next. Fig thought about this for a moment and then went and stood directly behind Tansy, so close that her tiny shell bumped Tansy's, politely, every few seconds.

The top shell crabs understood faster than she expected. One slid in behind Fig, noticed his mistake, and shuffled back to his place between the dog whelk and Tansy. Within a few minutes the pool held a row of six hermit crabs in order from large to small, with Boone at the front and the moon snail shell in front of Boone. Nobody had ever seen anything like it. The red anemone, which had seen a great deal, waved its tentacles slowly, the way it did at everything. Then a shadow slid across the sand, long and quick, and every crab in the line went cold, and the gull had landed on the rocks above the pool.

Part Three · Changing Coats

Nobody breathed. The gull walked along the edge with its head tilted, one yellow eye pointed straight down at them. A crab in a shell can hide, but a crab in the middle of a swap cannot. If Boone moved now, the whole line would have to step out of its shells at once, and the gull would feast, and Boone did not move. The line did not move. Even Fig held her breath so hard that her shell squeaked, and the gull strutted closer, closer, and stopped at the sandy end, looking down at the shiny purple shape lying in the sand. It was the biggest, brightest thing in the pool.

The gull stabbed its beak into the purple whelk and tugged. It was far heavier than it looked, and the gull flapped and tugged, then planted both feet and heaved with its whole body, and the shell lifted out of the sand with a long, sucking pop. It rose into the air, wobbled, dipped, and nearly landed on the gull's own head. The gull gave a scream that sounded like an insult in gull language, flapped three times, and flew away over the rocks with a huge empty shell swinging from its beak. It was never seen on that beach again, though some say it is still looking for the crab.

The silence in the pool lasted about four seconds. Then Boone went in. He went in the way he did everything, slowly, backing his whole weight into the moon snail shell and settling it on his back and rocking once to test the balance. Behind him the line held its breath, and the empty whelk lay on its side in the sand with the entire pool watching it. Then Boone announced that it would do, and the dog whelk crab was out of her shell and into his before he had finished speaking.

After that it went like water running downhill. The first top shell crab slid into the dog whelk, and the second into the first top shell. Then Tansy, with her heart pounding like the tide, backed out of her periwinkle, felt the cold water on her tail for one terrible moment, and pushed herself into the second top shell. It closed around her. She pulled in, and pulled in, and kept pulling until her claws came together across the opening like a door, and for the first time since June there was nothing of Tansy showing at all. From inside the dark it sounded as if the whole sea had gone a long way off.

When she came out again, Fig was sitting in the periwinkle. It fit her the way a good shell fits, closed and tidy and not a hair too large, and she was turning round and round in it, trying to see her own back. Six crabs had changed shells in the time it took a wave to pull off the shingle, and nobody had fought and nobody had been eaten. Boone, settling into his new weight, remarked that the purple whelk had turned out to be the most useful shell in the pool, and that it had never been better than when somebody else carried it off. The anemone waved, as if it agreed.

The tide came through the crack at noon and filled the pool to the brim. Tansy let the first wave lift her and set her down, and the shell stayed exactly where it was, balanced on her back as if it had grown there. She pulled in, and the water rolled over her and could not find her. When she came out, the pool was clear and bright, and the periwinkle that had been her house all summer was walking away through the weed with Fig's eyes looking out of it, extremely pleased, extremely small, and already a little too tight.