“There’s a camera in the box,” said Billy. “Hide beetles is their English name. They go through everything, just leave bones behind.”

The boy grinned and tugged his father’s hand. The rest of the group smiled, embarrassed. Flesh-eating bugs: sometimes life really was a B-movie.

Billy noticed one of the young men. He wore a past-it suit, a shabby-genteel outfit odd for someone young. He wore a pin on his lapel, a design like a long-armed asterisk, two of the spokes ending in curls. The man was taking notes. He was filling the pad he carried at a great rate.

A taxonomiser by inclination as well as profession, Billy had decided there were not so many kinds of people who took this tour. There were children: mostly young boys, shy and beside themselves with excitement, and vastly knowledgeable about what they saw. There were their parents. There were sheepish people in their twenties, as geeky-eager as the kids. There were their girlfriends and boyfriends, performing patience. A few tourists on an unusual byway.

And there were the obsessives.

They were the only people who knew more than the young children. Sometimes they did not speak: sometimes they would interrupt Billy’s explanations with too-loud questions, or correct him on scientific detail with exhausting fussy anxiety. He had noticed more of such visitors than usual in the last several weeks.

“It’s like late summer brings out the weirdos,” Billy had said to his friend Leon, a few nights back, as they drank at a Thames pub. “Someone came in all Starfleet badges today. Not on my shift, sadly.”

“Fascist,” Leon had said. “Why are you so prejudiced against nerds?”

“Please,” Billy said. “That would be a bit self-hating, wouldn’t it?”

“Yeah, but you pass. You’re like, you’re in deep cover,” Leon said. “You can sneak out of the nerd ghetto and hide the badge and bring back food and clothes and word of the outside world.”

“Mmm, tasteful.”

“Alright,” Billy said as colleagues passed him. “Kath,” he said to an ichthyologist; “Brendan,” to another curator, who answered him, “Alright Tubular?”

“Onward please,” said Billy. “And don’t worry, we’re getting to the good stuff.”

Tubular? Billy could see one or two of his escortees wondering if they had misheard.

The nickname resulted from a drinking session in Liverpool with colleagues, back in his first year at the centre. It was the annual conference of the professional curatorial society. After a day of talks on methodologies and histories of preservation, on museum schemes and the politics of display, the evening’s wind-down had started with polite how-did-you-get-into-this?, turned into everyone at the bar one by one talking about their childhoods, these meanderings, in boozy turn, becoming a session of what someone had christened Biography Bluff. Everyone had to cite some supposedly extravagant fact about themselves-they once ate a slug, they’d been part of a foursome, they tried to burn their school down, and so on-the truth of which the others would then brayingly debate.

Billy had straight-faced claimed that he had been the result of the world’s first-ever successful in vitro fertilisation, but that he had been disavowed by the laboratory because of internal politics and a question mark over issues of consent, which was why the official laurel had gone to someone else a few months after his birth. Interrogated about details, he had with drunken effortlessness named doctors, the location, a minor complication of the procedure. But before bets were made and his reveal made, the conversation had taken a sudden turn and the game had been abandoned. It was two days later, back in London, before a lab-mate asked him if it was true.

“Absolutely,” Billy had said, in an expressionless teasing way that meant either “of course,” or “of course not.” He had stuck by that response since. Though he doubted anyone believed him, the nickname “Test-tube” and variants were still used.

THEY PASSED ANOTHER GUARD: A BIG, TRUCULENT MAN, ALL SHAVED head and muscular fatness. He was some years older than Billy, named Dane Something, from what Billy had overheard. Billy nodded and tried to meet his eye, as he always did. Dane Whatever, as he always did, ignored the little greeting, to Billy’s disproportionate resentment.

As the door swung shut, though, Billy saw Dane acknowledge someone else. The guard nodded momentarily at the intense young man with the lapel pin, the obsessive whose eyes flickered in the briefest response. Billy saw that, in surprise-and just before the door closed between them-Dane looking at him.

DANE’S ACQUAINTANCE DID NOT MEET HIS EYES. “YOU FEEL IT GET cool?” Billy said, shaking his head. He sped them through time-release doors. “To stop evaporation. We have to be careful about fire. Because, you know, there’s a fair old bit of alcohol in here, so…” With his hands he made a soft explosion.

The visitors stopped still. They were in a specimen maze. Ranked intricacies. Kilometres of shelves and jars. In each was a motionless floating animal. Even sound sounded bottled suddenly, as if something had put a lid on it all.

The specimens mindlessly concentrated, some posing with their own colourless guts. Flatfish in browning tanks. Jars of huddled mice gone sepia, grotesque mouthfuls like pickled onions. There were sports with excess limbs, foetuses in arcane shapes. They were as carefully shelved as books. “See?” Billy said.

One more door and they would be with what they were there to see. Billy knew from repeated experience how this would go.

When they entered the tank room, the chamber at the heart of the Darwin Centre, he would give the visitors a moment without prattle. The big room was walled with more shelves. There were hundreds more bottles, from those chest-high down to those the size of a glass of water. All of them contained lugubrious animal faces. It was a Linnaean décor; species clined into each other. There were steel bins, pulleys that hung like vines. No one would notice. Everyone would be staring at the great tank in the centre of the room.

This was what they came for, that pinkly enormous thing. For all its immobility; the wounds of its slow-motion decay, the scabbing that clouded its solution; despite its eyes being shrivelled and lost; its sick colour; despite the twist in its skein of limbs, as if it were being wrung out. For all that, it was what they were there for.

It would hang, an absurdly massive tentacled sepia event. Architeuthis dux. The giant squid.

“IT’S EIGHT POINT SIXTY TWO METRES LONG,” BILLY WOULD SAY AT LAST. “NOT THE largest we’ve ever seen, but no tiddler either.” The visitors would circle the glass. “They found it in 2004, off the Falkland Islands.

“It’s in a saline-Formalin mix. That tank was made by the same people that do the ones for Damien Hirst. You know, the one he put the shark in?” Any children would be leaning in to the squid, as close as they could get.

“Its eyes would have been twenty-three or twenty-four centimetres across,” Billy would say. People would measure with their fingers, and children opened their own eyes mimicry-wide. “Yeah, like plates. Like dinner plates.” He said it every time, every time thinking of Hans Christian Andersen’s dog. “But it’s very hard to keep eyes fresh, so they’re gone. We injected it with the same stuff that’s in the tank to stop it rotting from the inside.

“It was alive when it was caught.”

That would mean gasps all over again. Visions of an army of coils, twenty thousand leagues, an axe-fight against a blasphemy from the deep below. A predatory meat cylinder, rope limbs unrolling, finding a ship’s rail with ghastly prehensility.

It had been nothing like that. A giant squid at the surface was a weak, disoriented, moribund thing. Horrified by air, crushed by its own self, it had probably just wheezed through its siphon and palsied, a gel mass of dying. That did not matter. Its breach was hardly reducible to however it had actually been.