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 fitted her properly. She could feel it every time a wave came through the pool. A hermit crab in a proper shell can pull herself 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 curl of her abdomen still showed at the back, pale and exposed, where anything with a beak could notice it. The shell had not shrunk. She had grown. That was how it went with hermit crabs, and nobody had ever discovered a way around it.

The pool where she lived was a long crack in the rocks at the bottom of a shingle beach, filled twice a day by the tide and abandoned twice a day when the water drew back. It held a red anemone, a scatter of periwinkles grazing on the weed, two shore crabs who kept to themselves, and nine hermit crabs of various sizes, every one of them living in a shell that some snail had made and then given up. That was the entire difficulty. Hermit crabs could not make shells. They could only find them, and every shell on the beach that was any good already had somebody inside it.

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 larger than a pea and lived in a periwinkle so tiny that she carried it like a hat. Fig had openly admired Tansy's shell all summer. Tansy was aware of this because Fig mentioned it, frequently, with the kind of hope that is not really a hint because it is not 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 shell nearly twice the size of Boone's, lying on its side in the sandy end, thick and heavy and streaked with purple. Tansy had looked at it every day since July. One evening, with her tail aching from a day of being partly outside, she decided that looking was no longer enough. She backed out of her periwinkle, which took courage, because for the length of a breath a hermit crab out of her shell is the softest thing on the beach, and she slid herself into the purple whelk.

It was like moving into a cavern. She could pull in so far that the light vanished and the sound of the water came from a long way off, and for a moment it felt like the safest place she had ever occupied. Then she attempted to walk. The whelk rolled. It was so heavy that every step was a hauling operation, and when the first wave of the evening tide came through the crack it simply lifted the shell, turned it over, and deposited it on top of her. She lay upside down with her legs working in the water, unable to right herself, until the wave retreated and she could scramble out.

Part Two · The Line

She crept back into her periwinkle with her tail showing and her pride somewhere behind her in the sand. Boone, watching from his ledge, observed that a shell could be too big as well as too small, and that a crab carrying a house she could not lift was a crab waiting to be flipped. 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 possibly be available now. 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 new 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 unbroken, with the snail long departed from inside it. It was not enormous. It was, Tansy judged, running her claw around the opening, exactly the size of Boone. Which meant that it was useless to her, and also meant that 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, and the whole group simply stayed there, turning the shell over now and then and settling again. Fig, who had come to watch, asked Tansy what everybody was waiting for. Tansy realized that she did not know. She had seen crabs fight over shells. She had never seen them wait.

The explanation, when it came to her, 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, each crab moving up one house. At the end of the line stood Tansy, who would receive the second top shell, a size she had been dreaming about since July. Nobody could move until Boone moved. And Boone, she saw now, was not moving because he was not certain, and a crab who abandons a good shell and discovers the new one is wrong has nowhere to return to. Everybody was waiting on one 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 they fit, and a crab in a wrong shell was back where she started. There was a better way to do it, and it involved standing in a line. She walked to the empty space directly behind the dog whelk crab and settled there with her claws folded, and when Fig asked what she was doing she said that she was being next. Fig considered this for a moment and then went and stood directly behind Tansy.

The top shell crabs understood faster than she expected. One moved in behind Fig, noticed the mistake, and shuffled back to his proper position between the dog whelk and Tansy, and the other took her spot behind him. Within a few minutes the pool held a row of six hermit crabs arranged 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. The tide was turning. They had, Tansy judged, until the water came through the crack.

Part Three · Changing Coats

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, and then, for a long moment, he did nothing at all. Behind him the line held its breath. The empty whelk lay on its side in the sand with the entire pool observing it. Then Boone announced that it would do, and the dog whelk crab was out of her shell and into his before he had entirely 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 going like the tide, backed out of her periwinkle, felt the cold water on her tail for one terrible instant, 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 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 in the sand, attempting to see her own back. Six crabs had changed shells in the time it took a wave to pull back off the shingle, and nobody had fought and nobody had lost. The purple whelk still lay in the sandy end, too big for anyone in the pool. Boone, settling into his new weight, remarked that somebody would eventually come along for it, and that when they did, it would be worth lining up for.

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 discover her. When she came out, the pool was clear and brilliant with light, 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.