The Lightkeeper's Daughter by Iain Lawrence

out.”
    “The hermit crab is a scoundrel, too lazy to build a shell.”
    The lessons made the children what they were. Alastair was sensitive; Squid was wild. The lessons inspired Hannah to go through Murray’s shelf of books, learning all she could of animals she had scarcely looked at before.
    Then Alastair turned ten.
    And Murray lectured on the barnacle.
    The cherries spread before her remind Hannah of that day. Crowded on the towel, they’re lumps beneath her hand. She touches them softly, gently, the way Alastair touched the barnacles.
    “They love company,” said Murray, squatting on the rocks below the tower. “They’re friendly as all get-out.”
    Squid was quieter than usual. They’d walked right around the island, and Hannah had feared that Murray wouldn’t be giving a lecture that day. But he’d only been watching for a big mass of barnacles, to better illustrate his point. There were so many barnacles she couldn’t see the rock underneath them. They covered it like stucco, in clumps as jagged as broken teeth.
    “See how they live in cities?” asked Murray. “In high-rises even, one atop another? But as children they go swimming through the ocean. They’re as free as butterflies, no shell to weigh them down.”
    He touched the barnacles. “Gather round,” he said.
    They found places at his elbows, Alastair right in front of him.
    “When a barnacle gets a little older he decides to settle down. He finds a city and gives up his wandering ways; he builds his own little house in the city. And in it he’ll live for all his days.”
    He ran his hand across them. “Look closely,” he said.
    They all bent down. The wind ruffled round them, and a flock of gulls went by above.
    “See how they live? They put up walls, a door at the top. Can you see how the shell is made in plates, with hinges and all the hardware? They’ve closed up shop because the tide is out, but their doors are still ajar.”
    Hannah leaned over them. The barnacles dug at her knees and the flesh of her hands. But she saw the doors and wondered how it was that she’d never noticed them before. They were beautifully formed, a pyramid of plates. And they all slammed closed as she brushed her hand across the shells.
    Beside her, Alastair was doing it too. She saw his face, the look of magic.
    “In every house there’s a barnacle,” said Murray. “They stick their heads to the rock with cement. The strongest glue in the world. And when the tide comes in they open their doors and poke out their feet. They thrash and kick at anything that drifts by. Their days of swimming are gone forever; they can never leave their houses. And at the slightest danger, they lock themselves inside. They bolt their doors and cower in the darkness.”
    He stood up. “There,” he said. “That’s what city life does to you.”
    Alastair was still staring at the barnacles, still stroking them kindly. Squid sat back and brushed her knees. The skin was red and mottled, speckled with barnacle dust.
    “Well,” said Murray, his hands on his hips. “Any questions? Then, there being none—”
    “Wait!” said Alastair.
    Murray frowned. There were never questions at question time.
    “How do they . . .” Alastair bit his lip. “You know. How do they—do that?”
    “You mean, how do they swim?” asked Murray, hopefully.
    “No,” said Alastair. “Have babies.”
    Hannah rolls the cherries under her hand and remembers how the question shocked her. She picks up the towel by its corners, folding them into a bulging ball.
    It was inevitable; she can see that now. Not once in his lectures had Murray mentioned reproduction. The lives of his animals began in childhood and ended in lonely solitude.
    Of course it was Squid who pressed the point. “Yes, Dad,” she said, springing forward again. “How do they do that? How
do
they have babies?”
    “Funny you should ask,” he said, and scratched furiously at his hair. “I think it was Aristotle who wrote