In desperation the Shadow clambers after me, but a funnel has formed in the water beneath the broken lodestone. It stretches far down and whirls violently, creating a magical vacuum which drags at the mass of shadows. The beast's rear tentacles are stiff behind it, drawn towards the vortex, and its body begins to lengthen and narrow. The creature strains against it, but the vacuum is too strong. There are laws which even the Shadow has to obey, at least for the time being.

In a rush, and with a hateful shriek, the Shadow's ripped away. It smashes through the lodestone, shattering the remains of the rock, and disappears down the funnel, howling all the way. Moments later the funnel collapses in on itself as swiftly as it formed.

I want to rush to Beranabus's corpse and bid him farewell. I'm weeping and all I want is to be by my dead friend's side. But that's not possible. Because now that the lodestone's magic has evaporated, the shield keeping the sea at bay has started to give way.

The fragments of the lodestone fall first, trickling through cracks in the invisible barrier. Water seeps up through the cracks, spreading neatly across the surface of the shield. Then one of the living dead stumbles and drops out of sight as if crashing through a thin layer of ice.

"Let's get the hell out of here!" Dervish shouts, hauling me through the door.

"Beranabus!" I cry.

"We can't help him now," Dervish pants. As he says it, the shield flickers out of existence and water floods the hold.

The ship lurches. A wave of foaming water surges towards us, washing away the helpless bodies of the zombies. We should be washed away too, but Sharmila acts swiftly to avert catastrophe, establishing a barrier around us and the doorway. The wave breaks and seethes away, the sea temporarily cheated of its victims.

"Quick," Sharmila gasps, hopping up the stairs. "The magic is fading. The barrier will not hold."

She's right. I can feel the energy ebbing away at a frightening rate. I look one last time for the body of Beranabus, but the ocean has already claimed it. Wiping tears from my cheeks, I hurry after Dervish and Sharmila, knowing that if we don't climb sharply, we'll soon be joining Beranabus in his watery grave.

We move a lot slower going up than we did coming down. It's not just the fact that we're climbing. We're tired and drained. We were fine when the air was thick with magic, but the unnatural energy is fading fast.

We're halfway up the second flight of stairs when I hear the sea gush up the corridors behind us. I've no idea how long we have. I imagine it would usually take a ship this size at least a couple of hours sink, but the hole in the hull was extremely large.

The zombies are still going strong. The strange magic of the Shadow which reanimated them is fading slower than the energy we were tapping into. While we're rapidly weakening, the zombies haven't been significantly affected.

We don't use bolts of magic anymore, or arrogantly dismiss them with a wave of a hand. We're reduced to close-quarters fighting. We can still repel them with our charged fists and feet-the magic hasn't disappeared entirely-but there are thousands of zombies. If we're still here when the last of the energy fades, they'll swamp us. Unless the sea claims us first.

Sharmila's second leg fragments. She pumps magic into it to hold the bones and scraps of flesh together.

"Don't bother," Dervish grunts, lifting her. "Save your strength. Get on my back. I'll be your legs. You keep the zombies off."

"What about your heart?" Sharmila shouts.

"It'll hold for a while."

I can move much quicker than Dervish now that he's burdened with Sharmila. I'm tempted to race ahead of them, up through the ship, away from the encroaching water. But they're my friends and they wouldn't desert me if I was in their position. If it becomes necessary to flee, I will. But as long as there's a chance we might all make it out alive, I'll stick with them.

I take the lead, knocking flailing, snarling zombies out of our way, pushing ahead, the undead humans crowding the staircase behind and in front. I should feel fear in the face of such warped, nightmarish foes, but my emotions are focused on Beranabus-there's only room within me for mourning.

I can't believe he's dead. It's hard to imagine a world without the ancient magician. He's been mankind's saviour for longer than anyone should have to serve. What will we do without him? I doubt the Disciples can repel the waves of Demonata attacks by themselves. Beranabus believed our universe created heroes in times of need. If that's true, perhaps someone will replace him. But it's hard to picture anybody taking the magician's place. He was one of a kind.

We hit another level. I'm about to lurch up the next set of stairs when I spot Kirilli Kovacs tussling with a gaggle of zombies. He's in bad shape, bitten and scratched all over. A dozen of the living dead surround him.

I should leave him. He doesn't really deserve to be rescued and I can't afford to waste any of my dwindling power. But I can't turn my back on a man just because he's a coward. Kirilli didn't betray or undermine us-he simply gave in to fear, as many people would have.

Drawing on my reserves, I mutter a spell and gesture at the zombies packed around Kirilli. They fly apart and a path opens. "Run!" I yell. Kirilli doesn't need to be told twice. He stumbles clear of the zombies and is by my side moments later. Blood cakes his face, but his eyes are alert behind the red veil. He starts to say something.

"No time for talking," I snap. "Get up those stairs quick, and if you fall, I'll leave you."

Kirilli flinches, draws a breath, then darts ahead of me, taking pole position, staggering up the seemingly endless flights of steps towards the upper deck and its promise of escape.

As we're forcing our way up another staircase clogged with zombies, Dervish gasps and collapses to his knees. One hand darts to his chest. I think it's the end of him, but Sharmila presses her hands over his and channels magic into his heart. She pulls a stricken face as she helps-the magic she's directing into his flesh means she has less to ward off the pain in her legs. But she has no real choice. Without Dervish to carry her, she's doomed.

Kirilli is struggling with the zombies. He's weak and afraid. He lashes out at them wildly, not preserving his energy or channelling it wisely. I've tried warning him, but he either doesn't hear me or can't respond. He knows only one thing-he has to go up. That's tattooed on his brain, driving him on.

Thankfully the walking corpses are moving more like regular zombies now. Their magic is fading. The attacks are clumsier, less coordinated. But they're still on their feet, our scent thick in their nostrils, licking their lips at the thought of biting into our soft, juicy brains.

As we hit the last step of another flight, Kirilli screams something unintelligible. I'm exhausted, but I push forward in reply to his cry, fearing the worst. But when I clear the step, I realise it was a yell of exhilaration, not dismay. We're back at the upper deck.

The ship is lurching at a worrying angle, and the deck is littered with hordes of zombies. But we get a fresh burst of hope when we breathe the fresh, salty air.

Dervish lays Sharmila down and squats beside her. "I need... a minute," he wheezes, face ashen, rubbing his chest.

"We can't stop," Kirilli shrieks, knocking over a zombie in uniform who's either the ship's captain or a highly placed mate.

"Shut up," I growl and crouch next to Dervish. "Let me help."

"No," he mutters. "Save your magic... for yourself."

"Don't be a fool." I shove his hands away and rest my left palm on his chest. I pump magic into him, enough to keep him ticking over.

"Do you know the way back to Kernel?" Sharmila asks, wincing from the pain in her thighs. They're bleeding at the stumps, the flesh we knotted together in the demon universe coming undone.

"Yes." I grin at her. "Perfect memory, remember?"

She returns the smile, but shakily. "Perhaps you should leave me here."

"We're not leaving anyone behind," I say firmly. "Except maybe Kirilli."

He stares at me with a wounded expression. "I hope you don't-" he starts.

"Not now," I stop him. My cheeks are dry. I must have stopped weeping at some point coming up the stairs. The ship is slipping further into the water. The angle of the deck to the sea is increasing steadily. Kernel's at the end of the ship which is rising. If we don't act quickly, we won't make it.

"Come on," I command. "One last push. We can rest once we slip through the window."

Dervish sighs wearily but staggers to his feet. He reaches for Sharmila. "Wait," I tell him and glance fiercely at Kirilli. "It's time you proved yourself worthy of rescue. Carry her."

"But I have a bad back," he protests. "I never lift anything heavier than-"

"Carry her," I repeat myself, "or I'll cut your legs off, glue them to Sharmila and let her walk out of here on your feet."

Kirilli gives a little cry of horror. He suspects I'm bluffing, but he's uncertain.

"I am not that heavy," Sharmila chuckles. "Especially without my legs."

"We're nearly there," I tell the stage magician. "You won't have to carry her far."

"Very well," Kirilli snaps. "But if I throw my back out of joint, I'll sue." He flashes me a feeble grin and picks up Sharmila. I help settle her on his back, then push through the zombies converging on us, lashing out with both my small fists, praying for the strength to stay on my feet long enough to guide us all to safety.

I'm almost fully drained. Only a sheer stubborn streak keeps me going. I refuse to fall this close to the end. It happened before, in the cave all those centuries ago. I almost made it out. I could see the exit as the rock ground shut around it. It was horrible to come up short with freedom in sight. I won't taste that defeat again.

Deckchairs and unbolted fixtures slide down the deck. Some of the zombies topple and slide too. Extra obstacles for us to dodge. The end of the ship continues to rise out of the water. A few more minutes and the angle will be too steep to climb. We'll slip backwards to perish with the zombies when the ship's dragged under.

We catch sight of the swimming pool. The window's still open and Kernel's in front of it. But he's struggling with a zombie. There are dozens around him and the window, separated from them by a circle of magic. But one has pierced his defences and is wrestling with him.

"Kernel!" I cry. "Hold on. We're almost with you. We-"

Kernel shouts something in response. He tries to tear himself away from the zombie, then reaches for its head to rip it loose-it's only attached by jagged strips of flesh to the neck. There's a flash of blinding light and we all cover our eyes, Kirilli dropping Sharmila out of necessity.

When I open my eyes a few seconds later, it's like looking at a bright light through several layers of plastic. I blink furiously to clear my vision. When I can see properly, I look for Kernel. The circle where he was is still in place. The zombies around it are all momentarily sightless, stumbling into each other, rubbing their eyes. But the window is gone. And where it stood-where Kernel and the zombie were battling-is an ugly swill of tattered flesh, clumps of guts, fragments of bones and several pints of wasted human blood.