Back on the roof. The Disciples killed several demons and the mage who'd been helping them. A few of the beasts fled through the window before it closed. The rest died here, helpless without magic, choking to death on our clean, human air, then rotting like the disgusting, hellish globs that they are.

The patients and staff inside the hospital are safe, although not many remain. They're being evacuated. A huge operation, still under way. I watched it with Beranabus while we were waiting for the others to join us. I'm impressed by how swiftly the people of this time can move in an emergency, how selflessly they rise to the occasion and risk all to help.

Sharmila is lying close by, unconscious. Beranabus removed her thighbones and has been working on the tattered flesh, sealing off veins and arteries, mending nerve endings where he can, destroying others to lessen the pain that Sharmila will experience when she wakes.

Dervish is sitting nearby on the trolley, head bowed, feebly stroking his beard, shivering from shock and the cold night air. His heart has held, but Beranabus had to help him climb the stairs, carrying him as Dervish had earlier carried Sharmila. Meera is sitting beside her dear friend, watching over him like a faithful hound.

Shark's by the staircase, ready to turn away anybody who ventures up this far. He enjoyed tackling the Demonata and ripping a few to pieces. He's delighted with his evening's work.

I'm bringing Beranabus, Grubbs and Kernel up to date, telling them about the werewolf attack, my gift of soaking up memories, what I sensed from the werewolf I touched, the assault at the hospital. Shark and Meera hadn't told them much-there wasn't time. It took them several weeks in the demon universe to find Beranabus. Thankfully they passed through zones where time moves faster than it does here.

"You're sure the Lambs masterminded the attack in Carcery Vale?" Grubbs asks. He's grown a few centimetres since I last saw him and towers above everybody. But he's lost some weight and doesn't look so healthy. His ginger hair has grown back-he was bald in the cave-but has been scorched bare in a few patches. There are dark bags under his eyes and an ugly yellowish sheen to his skin. He looks exhausted and distraught.

"I can't be certain," I admit. "We didn't see any humans. Sharmila wanted to go after the Lambs once Dervish was safe, but we decided to wait until we'd discussed it with you. The werewolves might have been the work of some other group..."

"But they were definitely teenagers who'd been given to the Lambs?" Grubbs presses.

"Yes. At least the one I touched was. I don't know about the others."

"They must have been," he mutters. "I've never heard of anyone outside our family being inflicted with the wolfen curse. But why?" He glances at Dervish. "Have you been rubbing Prae Athim up the wrong way?"

"I haven't seen her since she paid us that visit before Slawter," Dervish answers. "I've got to say, I don't have much time for Prae, but this isn't her style. I could understand it if they were after something-you, for instance, to dissect you and try to find a cure for lycanthropy-but there was nothing in this for them. Those who set the werewolves loose wanted us dead. The Lambs don't go in for mindless, wholesale slaughter."

"But if not the Lambs, who?" Kernel asks. The bald, chocolate-skinned teenager was blind when I last saw him, his sockets picked clean by demonic maggots. He's restored his eyes in the Demonata universe, but his new globes don't look natural. They're the same blue colour as before, but brighter, sharper, with tiny, flickering shadows moving constantly across the surface.

"I think Lord Loss was behind the attacks," I answer Kernel's question. "Maybe he realised I was part of the Kah-Gash and wanted to eliminate the threat I pose, or perhaps he just wanted to kill Dervish and me for revenge. The attack tonight by Juni Swan makes me surer than ever that he sent the werewolves. It can't be coincidence."

"Juni Swan," Beranabus mutters guiltily. "I'd never have thought poor Nadia could turn into such a hideous creature. I don't know how she survived. Your spirit flourished after death, but you're part of the Kah-Gash. Juni isn't. Lord Loss must have separated her soul from her body some way, just before her death. That's why he took her corpse when he fled. But I don't understand how he did it."

He broods in silence, then curses. "It doesn't matter. We can worry about her later. You're right-Lord Loss sent the werewolves. I cast spells on Carcery Vale to prevent crossings, except for in the secret cellar, where any demon who did cross would be confined. Even if he found a way around those spells, he would have been afraid to risk a direct confrontation. If he opened a window, the air would have been saturated with magic. You and Dervish could have tapped into that. You were powerful in the cave, stronger than Lord Loss in some ways. He probably thought humans and werewolves stood a better chance of killing you. But that doesn't explain why the Lambs agreed to help him. Or, if they weren't Lambs, how they got their hands on the werewolves."

"Maybe he struck a deal with them," Dervish says. "Promised them the cure for lycanthropy if they helped him murder Bec and me."

"Would they agree to such a deal?" Beranabus asks.

"Possibly."

"Prae Athim's daughter turned into a werewolf," Grubbs says softly. "She's still alive. A person will go to all manner of crazy lengths when family's involved." He winks at Dervish.

"An intriguing mystery," Beranabus snorts. "But we can't waste any more time on it. We have more important matters to deal with, not least the good health of Dervish and Miss Mukherji-they'll both be dead soon if we don't take them to the demon universe. Open a window, Kernel."

Kernel starts moving his hands, manipulating patches of light which only he can see. That's his great gift-he can open a window in minutes instead of hours or days, to any section of the demon universe. In the past he couldn't work his magic on this world, but he seems to have developed since I last saw him.

"I'm not going," Dervish says.

"You can't stay here," Beranabus retorts.

"I have to. They attacked me... my home... my friends. I can't let that pass. I have to pursue them. Find out why. Extract revenge."

"Later."

"No," Dervish insists. "Now." He gets off the trolley and weaves to his feet. Meera steadies him. He smiles at her, then glares at Beranabus.

"It would help if we knew," Meera says in support of her friend. "The attack on Dervish and Bec might have been a trial run. The werewolves could be set loose on other Disciples."

"That's not my problem," Beranabus sniffs.

"There's been a huge increase in crossings," Meera says. "We've seen five or six times the usual activity in recent months. The Disciples are stretched thinly, struggling to cope. If several were picked off by werewolves and assassins, thousands of innocents would die."

"It might be related," Kernel says, pausing.

"Related to what?" I ask but Beranabus waves my query away. He's frowning.

"This could be part of the Shadow's plan," Kernel presses. "It could be trying to create scores of windows so that its army of demons can break through at once. We'll need the Disciples if that's the case-we can't be everywhere at the same time to stop them all."

"Maybe," Beranabus says grudgingly. "But that doesn't alter the fact that Dervish will last about five minutes if we leave him here."

"I'll be fine," Dervish growls.

"No," Beranabus says. "Your heart is finished. You'll die within days. That's not a guess," he adds as Dervish starts to argue. "And you wouldn't be able to do much during that time, apart from wheeze and clutch your chest a lot."

Dervish stares at the magician, jaw trembling. "It's really that bad?"

Beranabus nods soberly. "In the universe of magic, you might survive. Here, you're a dead man walking."

"Then get him there quick," Grubbs says. "I'll stay."

"Not you too," Beranabus groans. "What did I do to deserve as stubborn and reckless a pair as you?"

"It makes sense," Grubbs says, ignoring the cutting comment. "If the attacks were Lord Loss trying to get even, they're irrelevant. But if they're related to the Shadow, we need to know. I can confront the Lambs, find out if they're mixed up with the demon master, stop them if they are."

"Is the Shadow the creature we saw in the cave?" I ask, recalling the dark beast who even Lord Loss seemed to be working for.

"Aye," Beranabus says. "We haven't learnt much about it, except that it's put together an army of demons and is working hard to launch them across to our world." He studies Grubbs, frowning as he considers the teenager's proposal. "You'd operate alone?"

"I'd need help," Grubbs says. "Shark and Meera."

"I want to stay with Dervish," Meera says.

"He'll be fine," Grubbs overrules her. "He has Beranabus and Bec to look after him. Unless you want to leave Bec with me?" He raises an eyebrow.

"No," Beranabus mumbles. "If you're staying, I'll take her to replace you."

"Then go," Grubbs says. "Chase the truth on your side. I'll do the same here. If I discover no link between Lord Loss and the Lambs, I'll return. If they are working for him, I'll cull the whole bloody lot."

Kernel grunts and a green window opens. "Time to decide," he tells Beranabus.

"Very well," the magician snaps. "But listen to Shark and Meera, heed their advice and contact me before you go running up against the likes of Lord Loss or the Shadow." He carefully picks up Sharmila and steps through the window with her. "Follow me, Bec."

I look around at the others, dazed by the speed with which things have been decided. Dervish is hugging Grubbs, squeezing him tightly, the way I wish he would have squeezed me all these long months.

"Are you OK with this?" Meera asks. "You don't want to stay?"

"I'll do what I must," I sigh.

"Take care of Dervish," Meera whispers.

"I will," I laugh, wishing I could remain with Meera instead of Dervish.

"Be wary," she croaks, dropping her voice even lower. "Beranabus has always been strongly driven, but he's almost insanely focused now. He says this Shadow he's been hunting is a massive threat to mankind and he's determined to defeat it at all costs. But he's old and fuzzy-headed. He makes mistakes. Don't let him lead you astray."

"I'll keep an eye on him," I promise.

Dervish and Grubbs complete their farewells and the elder Grady stumbles through the window, rubbing the flesh around his chest, fighting back tears.

"Sorry we couldn't have more of a chat," Grubbs says to me.

"Next time," I smile.

"Yeah," he grunts sceptically. I can tell he thinks there will never be a time for simple chat. We belong to the world of pitched battle and Grubbs believes we'll never escape it. I think he's right.

As Grubbs and Meera work their way across the roof to tell Shark about their new mission, I face Kernel Fleck. He's grinning at me sympathetically. "The world moves quickly when Beranabus is around," he says.

"What's it like through there?" I ask, nodding at the window.

"Bad." His grin slips. "The Shadow's promising the eradication of mankind and a new dawn of demon rule. Others have threatened that before, but it's convinced an army of demons-even powerful masters like Lord Loss-that it can make good on its vow. We could be looking at the end this time." Kernel puts one foot into the panel of green light bridging two universes and beckons half-heartedly. "Let's go."

I take one last look at the human world-the night is bright with fires from the crashed helicopter and police searchlights-then wearily follow Kernel into the den of all things demonic.