There would almost be a showdown between Grisamentum and the Tattoo, Billy thought, at last. But it would, rather, be between Grisamentum and Paul. Whatever Fitch’s plans had been or now were, Billy realised, Paul was not afraid of him anymore.

“Billy,” Collingswood said. “Mate. What the shit have you been up to?” She winked at him. “If you didn’t want the job you should’ve just said no, fuck’s sake.”

“Officer Collingswood,” he said. Found himself grinning at her for a second. She pursed her lips.

“What’s the plan then, geezer?”

“Come on,” Billy said. “Let’s move. You ready?” Simon looked terrified but nodded. They opened the lorry so he could stare at the kraken’s tank. Metabolise its position in his head. “Good man,” Billy said. “You know what’s going to happen?”

Billy had prepared his case in writing. It was a long and detailed message, which he had sealed in a glass bottle. “Shall we?” he said to Saira and Simon. “We need its permission.”

“And bearings,” Simon said. “I told you, I can’t do it without pretty precise bearings.”

Billy tapped the bottle. “I said all that. It’s in there. Don’t panic.”

The message in the bottle begged.

YOU SAID THE KRAKEN WAS NO LONGER YOURS. PLEASE, YOU HAVE TO help us. Even if it’s not one of yours, for the sake of the city where you’ve been for however long, please, we are asking you to use your neutrality and your power like when you helped against the Nazis. We need a safe place. We all heard about how the Tattoo wouldn’t face you that time, and we need that sort of clout again.

Everything is at stake, Billy had written. We just need to get past this night. And protect it. We are desperate. He pushed the message into the letter box.

They stood quietly in the dark. A man rode by them on a bike, with squeaking pedal-strokes. Fitch and the Londonmancers waited. The last krakenbit hid their teuthic tumourous amendations in the lorry. The sea inside the house did not answer the bottle for a long time.

“What’s happening?” Simon whispered.

“We can’t stick around forever,” Saira whispered.

Billy raised his hand, to rap the window, with a sense of blasphemy, when he was preempted. Something knocked instead from the inside. A slow beat through the curtain. A lower corner of the cloth moved. It was pulled slowly back.

“It’s showing us,” Billy said. “So you can see for coordinates, Simon. Do what you need to do.”

“Bloody hell,” said Saira. “I guess that’s permission.”

The curtain retreated from a corner of darkness. There was nothing visible behind it, until from deep within that dark came motions-insinuations in the pitch. They came closer, halting inches behind the glass. Staring out from the dim light that streetlamps shone into the room were tiny translucent fish.

Their ventral fins thrummed. They regarded Billy with see-through eyes. A suddenness came, a quick thing, viper-mouth agape, and the little fish were gone. The curtains gently eddied.

Lights came on in the dark room. The lights were moving. They came up on a grotto. A room full of sea. A living room, sofa, chairs, pictures on the walls, a television, lamps and tables, sunk in deep green water, investigated by fish and weeds. Those lights were the pearl tint of bioluminescent animals.

A living room, furnishings interrupted with coral, grazed on by sea cucumbers. The tassels of a lampshade moved with current, and an anemone waved its feathery stingers in filigree echo. Fish moved throughout, ghost-lit by themselves and their neighbours. Fingernail-sized things, arm-thick eels. By a sunken hi-fi riveted with barnacles, a fist-sized light moved like a long-armed metronome. The tick-tock light made Billy stare.

“Have you got it?” he said to Simon, with effort. “What you need?”

“I’ll have to move the water out, just before, in the right shape,” Simon murmured. He stared and itemised to himself according to the strange techniques he had perfected.

“Done,” he said. A moray glided from some dark, coiled around the sofa leg, tugged it into a new position, to make space for what was coming. “Okay,” Simon said. He closed his eyes, and Billy heard in the air around them the muttering of Simon’s last imbecilic vengeful ghost.

“He knows what I’m doing,” Simon said. “He thinks I’m going myself. He’s trying to stop me murdering me again.” He even smiled.

THERE WAS THE NOISE OF PAPER. “THEY’RE HERE!” FITCH LEANED from the lorry. “Grisamentum! He’s coming!”

“Are you ready?” Billy said.

“They’re coming,” shouted Fitch. The air of the street was filling with papers. They investigated front gardens. They came at the lorry, staring with ink-blot eyes.

“Whatever the bloody hell you are going to do I suggest you do it,” Collingswood said.

Simon went to the kraken’s tank and put his hands on it. He closed his eyes. Headlights moved across the face of houses. There was the familiar prickling sound, the sequin glimmer. It faded up and down, and the tank was no longer there.

THERE WAS A RUMBLING FROM THE HOUSE. A BURP OF WATER SPILLED from the letter slot. With no tank to brace him, Simon fell to his knees.

“Big,” he muttered. He looked up and smiled. His ghost howled.

The kraken was in the embassy of the sea. Billy and Simon and Saira stared at each other.

“Did we…?” said Saira.

“It’s done,” said Billy.

“Congratufuckinglations,” Collingswood said. “Now will you please get in sodding prison?”

“It’s safe,” Billy said. The paper raged and raged around them. Cars came closer and stopped. Papers began to batter them angrily, pelleting into missiles. Paul shifted his chest out, as if he, not the picture he bore, were the ink’s enemy. Billy heard a voice he recognised. Byrne shouting “Goddammit!” from somewhere, as she approached and saw the empty lorry. “Time to go,” he said.

Collingswood saw the motorcade of Grisamentum’s last troops. She appeared to consider her options. The other officer ran. “You cheeky little fucker,” she shouted at his back as he went. She jabbed the air in his direction, and his legs tangled and he went down hard enough to break his nose, but she turned away as he scrambled back to his feet and continued running. She let him go.

“You’re welcome to try to arrest Griz if you want, Collingswood,” Billy said. “Fancy that?”

“I do fancy that yeah, actually, blood.” Not that she was moving.

Saira hesitated. Simon was helping Fitch into the lorry. “Let’s get out of here,” Billy said. Marge and Paul scrambled in too, the vanguard of the papers harassing Paul in confused habitual animosity, thinking he was his adornment. Billy, Saira and even Collingswood wordlessly moved toward the lorry, but they had left it too late. Byrne was close, and she was directing two cars of gunfarmers toward the big vehicle.

“Shit,” said Saira, judging the distance. She caught Billy’s eye a moment. He nodded minutely and she indicated the lorry to go. It lurched from the kerb, its rear door flapping, a bewildered Londonmancer and Marge still leaning from its back, Marge shouting in protest as they left the others behind. But they were gone, around a corner, gone. Simon wailed, held out his hands like a baby. Billy grabbed him and hauled him away.

Saira kneaded the wall beside them and gave it a mossy weathered gateway. They got in out of sight. They hunkered by the wall of the sea-house and crept as Byrne and Grisamentum’s crew came near, ready to scatter into the streets the moment angry papers careened around them.

“They must be going spare,” Billy said.

“Fine bunch of mates you have,” Collingswood said.

“They left without us,” Simon said, loudly enough that Billy pinched his mouth shut.

“They didn’t have any choice,” Saira said. “I told them to. I’ll find them…”

They heard a loud slam. The wall faintly shook.

“What the hell?” Saira said. She and Billy stared at each other. The noise came again. “Oh my God,” Saira said. “He couldn’t be so stupid… The sea?”

Would he? They crept to the corner and looked.

The land could never defeat the sea. As Canute had illustrated for his fawning courtiers, tides are implacable. Even Tattoo, bluster notwithstanding, had known to duck that confrontation. It was just an inevitable rule.

But rules were what Grisamentum wanted to rewrite.

Scratch out the writing on the wall, rewrite the rules, rework the blueprint, using the inks stored in the ocean itself. Would he stop this now? All he needed was tonight.

This was why when Billy peered around the edge of brick, he saw the papers corkscrewing in impatience, he saw Byrne carrying a big bottle of her boss protectively, he saw gunfarmers on guard, and he saw their colleagues kicking and kicking like thugs and police at the front door.

The redoubt of the ocean in residence in London, this house was encircled in thalassic knacks. But part of its defence was the certainty that it would never be needed, and now the attack was backed by the unremitting focused hex attention of Grisamentum. Byrne squirted him with a turkey baster into the lock mechanism, onto the hinges. This close to his becoming, he was cavalier with the stuff of his substance. He wrote weakening spells on the innards of the keyhole. One more onslaught of boots.

“No no,” said Billy, trying very much to think of something, to gather a plan, but a gunfarmer stepped up and slammed his boot at the door, and it flew open. It flew open and threw the man aside, and with it came an onrush piston of water, a giant brine fist.