She glared. "My brain is frozen."

"Manipulate the snow just like you would water and you'll be fine."

The gloves Ghastly had made for her were the same as Skulduggery's, meaning she could click her fingers to generate a spark or feel the air to move an object. But for something like water, an element she hadn't spent much time practising with, she needed a bare hand. She took off her right glove, the cold closing round her skin and robbing it of its warmth. She did her best to ignore all that, and focused on making the compacted snow under her boots roll backwards like a wave. But nothing happened. The dynamics were totally different than with free-flowing water. She gritted her teeth and poured her magic into it, and the snow surged, whipping her feet out from under her.

"Found it," Skulduggery said from up ahead.

Growling, Valkyrie struggled up and clomped through the snow to where he was standing. Once, maybe, it had been a cave, but now it was just a mass of snow-covered boulders and rocks. "This looks just like everything else around here," she said. "Are you sure this is it?"

"There's evidence of a bridge out there," he said, nodding his head towards the ledge. "It must have connected this peak to the one next to it. Once all the equipment was shipped in, the bridge was destroyed and the entrance collapsed."

Valkyrie stamped her feet. "So how do we get in?"

Skulduggery pressed his hands against the rock. A moment later, Valkyrie heard a low rumbling. Dust fell. The wall of rocks shifted violently, tearing a hole in itself. Skulduggery stepped back.

"There," he said. "That's as much as I can do while still maintaining the integrity of the wall."

The hole was a narrow gash of an opening, slanting almost at a horizontal angle. Valkyrie was not a fan of tight spaces. "You want us to climb through there?"

"I'll go first," he said, "to make sure it's safe. Hold my hat."

She did so, and watched him crouch by the hole. He slipped his head and shoulders in first, manoeuvred around, then pulled himself through. She watched his shoes disappear.

"How is it?" she called. "What's on the other side?"

"A tunnel," he called back. His hand came through, fingers wiggling. "My hat, please."

She passed it to him, and crouched. She eyed the gap uneasily. Another tight space. "Are you sure I'll be able to fit?"

Skulduggery's face appeared on the other side. "Of course you will. I did."

"But you're a skeleton," she pointed out.

"Yes, but I'm big-boned. You'll be fine."

She looked behind her, at the swirling snow and vast empty whiteness of it all, and sighed. She put her arms through first, getting a good grip, and then put her head and shoulders through. The other side of the cave wall was warm much too warm to be natural. Skulduggery held fire in his hand so she could see what she was doing. Grunting slightly, she climbed in further, her chest scraping along the rock. When she was halfway through, she slipped sideways a little, down the slant. She tried to pull herself through.

"I'm stuck," she said.

"No, you're not," Skulduggery told her. "Just wriggle, you'll be fine."

"I'm stuck," she insisted, and started laughing despite herself.

Skulduggery tilted his head. "I thought you didn't like tight spaces."

"I don't. I'm kind of panicking, but my bum is jammed. How can you not laugh when your bum is jammed? Help me."

He took her hands and pulled.

"Oh my God," she said, doing her best to stop giggling, "that's doing absolutely nothing. Could you please get me out of here?"

"But of course, dear." He reached in, gripped her waistband and pulled her out of the narrower end. He hooked his hands under her arms and dragged her the rest of the way through. Once back on her feet, she brushed the dust from her clothes and took off her mask, grinning at him.

"Never mention this to anyone," she said, stuffing the mask and gloves into her jacket.

"Your secret is safe with me."

They walked down the sloping tunnel, holding fire in their hands until the darkness shifted to mere gloom, and then brightened. They let the flames go out and proceeded cautiously.

The ground turned into a metal grille. Thick support struts criss-crossed overhead and glowing orbs hung from them, as if someone had caught handfuls of daylight and brought them underground. They passed through corridors of rock walls. The air was fresh, and carried a scent of cut grass and flowers. It was a warm summer's day down here in this mountain.

A bird flew past, disappearing around the corner.

"Well," Valkyrie said, "that's just unexpected, is what that is."

They walked on until the corridor widened, and in this widened corridor a man wandered by. Valkyrie recognised him from his file. Kalvin Accord. Adept, specialising in science-magic. Now dressed in what looked like a bathrobe and sandals.

"Kalvin," Skulduggery said gently.

Kalvin whipped around, eyes wide. Stared at them.

Skulduggery took a step forward. "Sorry. We didn't want to startle you. How are you?"

"Oh, this isn't good," Kalvin murmured. "Oh, this isn't good at all."

He turned and ran.

Skulduggery glanced at Valkyrie, and they started jogging after him.

"Kalvin," Skulduggery called. "There's nothing to be worried about. Please, just stop and talk to us."

But Kalvin kept running. Granted, it wasn't a very impressive run there's only so fast a person can move wearing sandals. He stumbled and one of the sandals came flying off, and he went on without it. Valkyrie picked it up on the way past.

Skulduggery caught up to him and they ran side by side. "Hi, Kalvin," he said.

Kalvin whined.

Valkyrie appeared at his other elbow. She held the sandal out as they ran. "I picked this up for you."

Kalvin was panting. "Thank you," he said, taking it from her.

"Why are you running away from us?" she asked.

"I'm not sure," he answered. "But now that I'm doing it, I may as well keep going."

"Except you're not really running away from us," Skulduggery pointed out.

"True," he gasped. "But I don't think I can stop. I want to stop. I do. But I don't think I can."

"Just slow down," Valkyrie said. "Come on, just slow down. That's it. A little more."

They slowed the run back to a jog, and Kalvin's legs started to wobble. He veered away from them and ran into the wall, then collapsed and rolled across the floor, clutching his side.

"Stitch," he explained when they looked down at him.

"You don't get an awful lot of exercise down here, do you?" Skulduggery said.

"Not really..."

"Do you want a hand up?"

"If it's OK with you... I'll just stay down here... for another moment."

"No problem."

"Why... why are you here?"

"It's about Argeddion."

"Then you're going to want to talk to Tyren." Kalvin took another few breaths, and sat up. "He is not going to be happy to see you."

yren Lament was definitely not happy to see them. Skulduggery and Valkyrie sat at the long table in the dining hall, and Lament stood looking at them with his arms crossed. He looked to be around forty, with long fair hair. He had a long nose and sharp, intelligent eyes. He was dressed identically to Kalvin. From the glimpses Valkyrie had snatched of the other sorcerers on the way here, robes and sandals seemed to be the uniform for mountain-dwelling mages.

"How did you find us?" were his first words to them.

"It wasn't easy," Skulduggery said.

He looked annoyed. "It was supposed to be impossible. We didn't go to all this trouble to be 'hard to find'. We did it to disappear."

"We'd never have come looking for you if it wasn't for Argeddion," said Valkyrie. "He's doing something to ordinary people, giving them magic."

Lament shook his head. "Impossible. No one can transfer magic in any way to anyone who doesn't already have magic within them."

"For all we know," said Skulduggery, "these mortals did have magic within them. But if they did, it was dormant. They didn't know anything about it."

"And what do you think Argeddion has done to them? Because whatever you suspect, I can assure you, he didn't do it. He's been resting in a coma-state for the past thirty years."

"You're sure?"

"Quite sure. He is closely monitored at every moment. The slightest increase in neural activity would be picked up on. Whoever is doing this to the mortals, it's not Argeddion."

"If it's not," said Skulduggery, "then it's someone connected to him somehow. We'd like to see him, all the same."

"I'm afraid I can't allow that."

"Why not?"

"Because I don't want to. You've already breached our outer perimeter I can't allow you to breach the inner one. I knew you thirty years ago, Skulduggery, but a man can change in thirty years."

"You don't trust me."

"I don't. And I don't even know your companion."

"We've saved the world," Valkyrie said.

"And on behalf of this little part of that world, I thank you," said Lament. "But you're still not getting close to Argeddion, I'm sorry."

Skulduggery sighed, and sat back. "Can we ask about the facility here?"

Lament sat opposite them. "Of course."

"How many can it hold?"

"I'm not sure what you mean."

"If there were another sorcerer like Argeddion, someone who found out their true name, could they be kept here, too?"

Lament paled. "There's another?"

"This is just hypothetical."

"Hypothetical questions are a prelude to actual questions," Lament said. "You told me that once. There is another?"

"There might be," Skulduggery admitted. "Hopefully, there won't, but there might be. Maybe your psychics here have picked up on it. A sorcerer named Darquesse."

Lament nodded. "We've heard of her. We didn't know that's how she got her power, though. Do you know anything about her?"

"No one does," said Skulduggery. "All we have is the vague promise that she will eventually turn up. How would you stop her?"

"If she hasn't realised who she is yet, I'd use her true name against her."

"And if she's already sealed it?" Valkyrie asked.

Lament exhaled slowly. "Then you're in trouble. You want to know how we subdued Argeddion, don't you? You want to use this technique against Darquesse? I'm afraid you travelled all this way to be disappointed."

Skulduggery tilted his head. "So how did you stop him?"

"There really was nothing to stop," said Lament. "From what I've been told, Darquesse will be a force of destruction. How she comes to be this way, no one knows. But Argeddion was not like that."

"We spoke with Greta Dapple," Skulduggery said. "According to her, Walden D'Essai was a pacifist. When he became Argeddion, this didn't change."

Lament nodded. "This is true, but... Up until D'Essai, eight sorcerers over the course of human existence have learned their true names. Eight that we know of, anyway. Three of these were killed soon after, before they could exploit what they'd learned. Two of them couldn't control their power and ended up killing themselves. Two more had their true names used against them and became virtually powerless. And the eighth one simply vanished. We presume he obliterated himself. No one who has ever learned their true name has been able to live peacefully."

"So while Argeddion was a pacifist and showed no inclination towards violence, you didn't want to take the chance that he could change his mind."

"It wasn't an easy decision to make. I liked Walden. He was a good man. I trusted him. I couldn't trust Argeddion. How could I? All it would take is one bad day. Maybe that's what sets Darquesse off. Maybe she's a normal sorcerer, doing good work, but sometime in the near future she's going to have one really bad day, and she'll make the world suffer for it."

"So what did you do?"