Ben’s aunt kept the lighthouse.

Not the light. The light kept itself, these days, on a timer, going round and round all night without anyone having to wind it. But somebody had to live there and keep the rest of it, the stairs and the windows and the little house at the bottom, and check the light was doing its job, and that was Aunt Jess. She had a cat called Salt, and a boat, and a kettle that took ages, and Ben was staying for one night.

He had never slept in a lighthouse. He had never known anyone who had.

It stood on a rock at the end of a long low bit of land that went out into the sea, and you got to it along a path, and at high tide the path was under the water and you did not. Aunt Jess had met him at the start of the path at low tide with a torch and a rucksack for his things, and they had walked out along it with the sea on both sides, going shush, shush, in the dark.

“Mind the green bits,” she said. “They’re slippy.”

He minded the green bits.

The lighthouse was white, and round, and taller than he had thought, and the little house at the bottom of it had a red door. Inside it was warm, and it smelled of toast and wet rope. Salt was on the chair by the stove. Salt was white, with one grey ear, and he opened one eye when Ben came in and looked at him for a long time, and closed it again, and Ben felt that he had been examined and allowed.

“He’ll come round,” said Aunt Jess. “He takes his time.”

They had toast. They had eggs. The kettle took ages, as promised. And then Aunt Jess said, “Want to see the light?” and Ben said yes before she had finished.

The stairs went round and round inside the tower, up and up, iron steps with the sea sound coming through the walls, and small round windows every so often with the dark outside. Ben counted the steps and lost count and started again. Salt came too. Nobody asked him to. He went ahead of them, tail up, taking the stairs as if he had built them.

At the top was the light.

It was bigger than Ben. It was made of glass, in rings and ridges like a giant’s boiled sweet, and it turned, slowly, on its own, and each time it came round it sent a great beam out across the sea and away, and away, further than he could see, and then swung on and sent another.

“Can I stand in it?” he said.

“You can stand next to it. Don’t look straight in.”

He stood next to it. He put his hand on the rail and looked out. There was the sea, all round, black and moving, with the beam going over it and showing him waves, for a moment, and then dark, and then waves again. There was the land behind, with a few lights on it, small and yellow. There was nothing else. It was the most nothing he had ever seen, and it was not frightening at all. It was just very big.

“Ships see this?” he said.

“Ships see this. They see it and they know where the rocks are, and they go round.”

“Every night?”

“Every night. Even if there’s no ships. That’s the point of it.”

Salt had sat down by the glass, in the warm, and was washing one paw. He did not seem impressed by the light. He had seen it before.

They stayed up there a long time. Aunt Jess pointed out the shape of the headland and the place where the boats came in, and once, far out, a light that was a ship, going very slowly along the edge of the world. Ben watched it until it was gone. Then his aunt said, “Bed,” and he said, “Five more minutes,” and she said, “That was five minutes,” and it had been.

His room was in the little house, at the top of the wooden stairs, under the roof. The window looked out to sea. The bed was narrow and high, with a blanket that smelled of the cupboard, and the pillow was very soft. He got in. Aunt Jess said goodnight from the door and went down.

And then it was just him, and the sea, and the light.

He had thought it might keep him awake. It did not. It came round the room, slow, a soft pale sweep across the ceiling and the wall and away, and dark, and then again. Like breathing. Like somebody stroking the room to calm it down. He counted the sweeps. He got to eleven.

There was a small thump, and the bed moved.

Salt had come up. He walked along the edge of the blanket, the way cats do, without any sound and with great importance, and stood on Ben’s chest, and looked down at him from very close, with the light going over them both.

“Hello,” said Ben.

Salt turned round twice and lay down. He was warm and heavy and he began, very quietly, to purr. Ben put his hand on him. Salt let him.

He must have slept a bit then, because the next thing was that the room was different, and the light was still going round, but there was something else. A sound. From outside. A long, low, breathing sound, out on the water, like the biggest sigh in the world.

Ben sat up. Salt grumbled and moved to the pillow.

He went to the window.

The light swept out across the sea, and for a moment, in the beam, far out, there was a shape. Long. Dark. Rounded. It came up, slowly, and there was a soft white puff above it that caught the light and hung there, and then the shape went down again, and the sea closed over it, and the beam swung on.

Ben waited.

The beam came round. Nothing. Round again. Nothing. And then, further along, the shape came up once more, and breathed, and the sound came across the water to him, low and long, and it went down.

“Whale,” he whispered.

Nobody heard him. Salt was asleep. Aunt Jess was asleep. The whale was going along the edge of the light, slowly, the way the ship had, coming up and breathing and going down, and each time the beam found it, and each time it let it go.

He watched until he could not see it any more. Then he watched some more, in case. Then he got back into bed, very carefully, so as not to move Salt, and lay down.

In the morning he would tell Aunt Jess, and she would say, “They come past sometimes, this time of year,” as if it were nothing, and he would know that it was not nothing. It was the most something there had ever been.

But that was the morning.

Now there was the bed, and the blanket that smelled of the cupboard, and Salt, warm against his ear. There was the sea, going shush, shush, all round the rock. There was the light, going round, and round, and round, slow and pale across the ceiling, so that ships could see it, and whales could see it, and Ben, with his eyes nearly closed, could see it too.

Round. And round. And round.