I step through the window and find myself on a highly polished wooden floor. There are no walls or ceiling, only a clear blue sky and glaring sun far overhead. I squint and cover my eyes with a hand. When my pupils adjust, I slowly lower my hand and stare around with awe.

We're surrounded by water-we must be on a boat. Everywhere I look, an ocean stretches ahead of me, small waves lazily rippling by. I've only seen the sea once before and that was from the safety of land. Finding myself stranded in the middle of it makes me feel sick. Even though the floor is steady, my legs seem to wobble beneath me and I have to fight to calm my stomach.

"Easy, Little One," Beranabus murmurs, touching my arm and smiling.

"It's so vast," I whisper, eyes round.

"Aye, but it's only the sea. You've nothing to fear."

"But the monsters..." I catch myself. In my time we thought the sea was home to an array of terrors. Now I know that isn't so. I remind myself that I'm not living in the fifth century any longer. Frowning at myself for overreacting, I order my legs to steady and my stomach to stop churning.

Breathing more calmly, I pivot slowly and study the vessel on which we've landed. We're on the deck of a massive ship, a luxury cruise liner, but its grandeurs have been spoilt by a recent, vicious attack. Deckchairs are strewn everywhere. We're close to a swimming pool-the water is red and there are bodies floating in it. A man lies spread-eagled on a diving board, blood dripping from his throat into the water. More corpses dot the deck and some are draped over deckchairs.

There are carcasses everywhere. Freshly dead, with blood oozing from them. Men, women and children. Some are in crew uniforms, others in swim wear or casual clothes. Apart from the soft dripping noises of the blood, there's no sound, not even the chug of an engine. The boat is as dead as the butchered passengers and staff.

As I gaze with horror at the carnage, the more experienced Sharmila checks a few of the bodies to ensure they're beyond help. "Juni could not have killed all these people by herself," she says quietly.

"She could," Beranabus grunts, "but I don't think she did. You can see different marks if you look closely. A group of demons had a party here."

"Where are they now?" Dervish asks, fingers flexing angrily.

"That's what I'd like to know." Beranabus walks to the diving board, steps on to it and pushes the body off into the water as if it was a rubbish bag-he can be as detached as a demon when he needs to be. The splash disturbs the silence. We wait edgily, but nothing reacts to the noise.

"Are you sure Dervish and Sharmila are safe here?" I ask Kernel, trying to find something other than the corpses to focus on. "There's magic in the air, but I'm not sure it will hold."

"It's secure," he assures me. "We wouldn't have brought them over if we had any doubts. We're surrounded by a bubble of magical energy. The entire ship's been encased."

"Like the town of Slawter," Dervish notes, then tugs anxiously at his beard. "This bubble-it's pretty impenetrable?"

"Yes," Kernel says.

"So if the window to the oasis blinks out of existence, we're trapped."

Kernel smiles. "Don't worry. I'll keep it open. That's what I excel at."

Beranabus returns from the diving board. "They must have a lodestone on board. No demon could maintain a shield like this without a lodestone."

Lodestones are stones of ancient-Old-power. Demons can use them to seal off an area and fill it with magic. That lets them operate as if they were in their own universe. They can use them to open tunnels as well, if the stone is especially powerful. But they need human help. They can't do it alone.

Lodestones are rare. When the Old Creatures inhabited the Earth, they used the stones to help keep back the Demonata. But in their absence the demons learnt to turn the magic of the stones against the humans they were originally intended to protect. Beranabus scoured the world for lodestones centuries ago and destroyed as many as he could find, or sealed them off like the one in Carcery Vale. But some evaded him and remain hidden in various corners of the world. Every so often a mage or demon tracks one down and trouble ensues.

"Is Juni still here?" Dervish asks Kernel.

"Yes," I answer first. "I sense her near the bottom of the ship."

"This feels like a trap," Sharmila mutters.

"Aye," Beranabus says. "But you learn to live with traps when you're chasing demons." He looks around. "Are there any others, Bec?"

I let my senses drift through the areas below deck. "There's one demon with Juni. Not very powerful. If there are others, they're masking themselves."

"There's a window open down there," Kernel says.

"Fairly ordinary. Only weaker demons can cross through it."

"Could there be armed humans?" Dervish asks.

"Perhaps," I mutter. "Humans are harder to sense than mages or demons."

"We can handle a few soldiers," Beranabus barks. "I'll turn their guns into eels-see how much damage they can do with them then!"

"We should go back," Sharmila says. "Juni has set this up to ensnare us."

"Why would she be expecting us?" Dervish argues.

"Lord Loss may have reasoned that we would target Juni. Perhaps everything-the attacks on Dervish, Juni revealing herself on the roof of the hospital-was designed to lure Beranabus here. The demon master might be poised to cross and finish us off personally."

"Not through that window," Kernel insists.

"Then through another," she counters. "We have never been able to explain why Lord Loss can cross when other masters cannot, or how he goes about it."

Beranabus considers that, then sighs. "You could be right, but we might never get a better shot at Juni. If she's not expecting us, it's the perfect time to strike. If she is and this is a trap, at least we can anticipate the worst. The magic in the air means she'll be dangerous, but it serves us as much as her. If Lord Loss doesn't turn up, we can match her. If he does cross, we'll make a swift getaway."

"Are you sure of that?" Sharmila scowls. "If we have to open a new window..."

"We won't," Beranabus says. "Kernel will stay here and guard our escape route. You'll know if any other windows open, won't you?"

"Yes," Kernel says.

"Then keep this one alive and watch for signs of further activity. If you sense anything, summon us and we'll withdraw. Is everyone satisfied with that?"

He looks pointedly at Sharmila. She frowns then shrugs. Taking the lead, Beranabus picks his way across the bloody, corpse-strewn deck and the rest of us cautiously, nervously follow.

My feet are soon sticky with blood, but I ignore my queasy feelings. This isn't the way the world should be, having to creep through pools of blood, past dozens of slaughtered humans. But when you find yourself in the middle of a living nightmare you have two choices. You can cower in a corner, eyes shut, praying for it to be over. Or you can get on with things and do your best to deal with the job in hand. I don't think I'm particularly brave, but I like to think I've always been practical.

We undertake a circuit of the upper deck before venturing into the depths of the ship, making sure there aren't any surprises waiting for us up here if we have to make a quick getaway. We don't find any demons or soldiers in league with the Demonata. Just one corpse after another, slowly frying beneath the merciless sun.

We're passing a row of lifeboats when I feel a twitch at the back of my eyes. It's the subtlest of sensations. I'd ignore it any other time. But I'm trying to be alert to the least hint of anything amiss, so I stop and focus. The twitch draws me to the third boat ahead of us. It hangs from hooks high above the deck.

"What is it?" Beranabus whispers. I feel magic build within him. He's converting the energy in the air into a force he can use.

"Somebody's there." I point to the lifeboat. "A man. Hiding from us. He's using a masking spell."

"Get ready," Beranabus says to the others. He points a finger at the hooks. They snap and the boat drops abruptly, landing hard on the deck. The man inside it yelps and tumbles out as the boat keels over.

Sharmila and Dervish step ahead of Beranabus, fingers crackling with pent-up magic. The man shrieks and wildly raises his hands, shouting, "I surrender!"

"Wait!" Sharmila snaps, grabbing Dervish's arm. "I know him."

The man pauses when he hears Sharmila's voice. He stares at her shakily as if he doesn't believe his ears or eyes.

"Kirilli Kovacs," Sharmila says.

"I... I recognise you... I think," he croaks.

"We met several years ago. You were with Zahava Lever. She was your mentor. My name is Sharmila-"

"-Mukherji," the man says, breaking into a big smile. "Of course. Zavi spoke very highly of you. She said you were a great Disciple, one of the finest. I should have recognised you immediately. My apologies. It's been a hard few..." He frowns. "I was going to say days, but it's only been hours."

"This is one of your lot?" Beranabus sniffs. We're all a bit mystified. The man is wearing a dark suit, but there are silver and gold stars stitched into the shoulders and down the sides. He sports a thin moustache and is wearing mascara. He looks like a stage magician, not a Disciple.

"This is my cover," he explains sheepishly. "I ran into fiscal complications..." He clears his throat. "Actually I gambled away my cash and my credit card was taken from me by a woman in... but that's another story. I had to get on the ship. I could have used magic but it was easier to get a job. So I did, as Kirilli the Konjuror. I've used this disguise before. It's always been effective. I can put on a first-rate stage show when I have to."

"Your standards are slipping," Beranabus says to Sharmila. "I might have to review the recruiting policy of the Disciples."

"I'm of a first-rate pedigree, sir," Kirilli snaps. "Even the best of us can fall prey to the occasional vice." He tugs the arms of his jacket straight and glares.

"Zahava said Kirilli was an excellent spy," Sharmila says. "He is very adept at trailing people and hiding from them. The fact that he survived the massacre here is proof of that. The Disciples need spies as much as they need warriors."

"Precisely," Kirilli huffs. "There's a man for every job, as my dear departed father used to say."

"I bet he worked in sewerage," Dervish says drily.

Kirilli flushes, but ignores the jibe. "By the way," he says stiffly, "I didn't catch your names."

Beranabus shrugs. "This is Dervish Grady. That's Bec. I'm Beranabus."

Kirilli's jaw drops and he loses his composure completely.

Beranabus winks at me. "I have that effect on a lot of my idolising Disciples."

"Only until we get to know you," Sharmila mutters, then addresses Kirilli again. "Can you tell us what happened? Swiftly, please-we do not have much time."

"That's really Beranabus?" Kirilli says, wide-eyed. "I thought he'd look more like Merlin or Gandalf."

"He'll turn you into a hobbit if you don't start talking," Dervish growls.

Kirilli blanches, then scowls. "I was tracking a pair of rogue mages," he says, adjusting his bow-tie-I spot a playing card up his sleeve. "They were planning to open a window."

"Why didn't you stop them?" Dervish asks.

"They were working for somebody else, taking orders from a superior. I wanted to expose their partner. I felt that was more important than stopping the crossing, although I hoped to do that as well."

"No prizes for guessing who their boss was," Dervish grimaces. "Ugly cow, disfigured, covered in pus and blood?"

Kirilli nods and shivers. "They were in regular contact, but I couldn't get a fix on who they were talking to. From what I overheard, it sounded like there were no imminent plans to open the window. They made it sound like they'd be on the boat for months, waiting for an order to act.

"They either knew I was eavesdropping and said that to fool me, or there was a change of plan. Either way, they opened the window earlier today. About twenty demons spat through and set to work on the crew and guests. I managed to shield myself. That's all I could do. There was no point fighting them-I wouldn't have stood a chance." He looks at us appealingly.

"You did all you could," Sharmila says kindly. "You are a spy, not a warrior. Besides, Disciples never fight when the odds are stacked against them. You have no reason to feel guilty."

Gratitude sweeps across Kirilli's face. "I expected the window to close after a few minutes but it stayed open and there was more magic in the air than I've ever experienced. The demons went on torturing and slaughtering. They took most of the people below deck. Maybe the sun bothered them and they wanted to do their work in the shade."

"No," Beranabus grunts. "Lodestones need blood. They were feeding it."

"What's a lodestone?" Kirilli asks but Beranabus waves at him to continue. "Balint and Zsolt- the mages-remained up top. They did their share of killing but nothing to compare with the demons. Not long before you lot arrived that woman... that thing crawled up from below." He shudders. "I wasn't sure if she was human or Demonata. I'm still not certain."

"I doubt if she knows herself anymore," Beranabus says softly.

"She barked orders at the demons and they killed the last few survivors," Kirilli goes on. "Then they retreated through the window and the woman said a spell to close it. Balint and Zsolt were grinning, mightily pleased with themselves, but she turned on them. Melted them into twin pools of bloody goo. Laughed as they screamed for mercy. Told them they were fools to trust the word of a monster. She lay down and wallowed in their juices when they were dead, then went below deck. That's when I climbed into the lifeboat."

"Interesting," Beranabus murmurs. Then he winks at Sharmila. "This definitely stinks of a trap."

"So we will leave?" Sharmila asks eagerly.

Beranabus chuckles. "I've walked into more traps over the centuries than I can remember. The Demonata and their familiars think they're masters of cunning but they haven't got the better of me yet. Let Juni and Lord Loss spring their surprise. I'll blast a hole in it so big, you could sail this ship through."

"Are you sure?" Dervish asks uneasily. "Juni was your apprentice. She knows all about you. Maybe you have a weak spot which she plans to exploit."

Beranabus shrugs. "I love a challenge."

"I really do not think we should-" Sharmila begins.

"We've no choice," Beranabus snaps. "She's our only link to the Shadow. It's a gamble, but this is a time for gambling. I don't think you understand the stakes. This is the end game. We don't have the luxury of caution. If we don't risk all and find out who the Shadow is and what its plans are, the world will fall." He waves at the corpses around us. "A world of this, Sharmila. Is that what you want?"

"Of course not," she mutters.

"Then trust me. We're precariously balanced and I might be testing one trap too many, but we can't play safe. It's all or nothing now."

"You truly believe matters are that advanced?" Sharmila asks.

"Aye." Beranabus's eyes glitter. "The Disciples have exercised caution over the years because there have always been other battles to fight. But this could be the final battle. Ever. Better to risk all on a desperate gamble than play it safe and hand victory to the Shadow. Aye?"

Sharmila hesitates, then smiles shakily. "Aye. If we fail, at least I will have the pleasure of saying, 'I told you so'."

"That's the spirit," Beranabus booms and heads for the nearest door. Without any sign of fear he leads us down into the bowels of the ship in search of the vile viper, Juni Swan.