Then the wall next to it slid open, and Wolfe stepped into another, hidden corridor. The eye of Horus was inscribed on the tiles that lined the hall.

‘I had heard this place had secret tunnels,’ Thomas said. He kept his voice low, but it echoed all the same. ‘I thought they were all ancient. Abandoned.’

Not this one. It was modern, and lined with inset statues that melded Greek, Roman and Egyptian influences in the odd style that Alexandria had developed; the first, a Scholar in a Greek tunic, held a scroll. The next, in a Roman toga, held an open book. The third was one of the Egyptian deities … Thoth, who had invented writing, and served as the god of scribes. He held the feather of Ma’at.

All, Jess realised, were automata. If a threat was found in the hall, it would never make it out alive.

Jess got all of this in hurried glances, because Wolfe was moving at a quick pace to the end of the hallway, which ended in another empty wall. He used his Library band on it, waking more symbols, and another entrance opened.

The Obscurists built these passages. He looked at Morgan, who’d put her hands in her dress pockets as she walked, as if she was cold. He remembered how the string of orange light from the blank had clung to her fingers. She was afraid to touch anything, for fear she might call something up that others could see.

Jess followed her into a small, plain anteroom lit by amber glows. No books here. No blanks. No reading tables or couches. In one corner was a stack of black canvas bags.

‘Pick up your packs,’ Wolfe said. ‘Your names are on tags.’

Thomas got there first. Even for his bulk, the pack he selected seemed large. When Jess grabbed the one with BRIGHTWELL on the tag, he was staggered by the weight. He slipped the straps on his shoulders. It fitted well enough, and having the load distributed made it feel more manageable.

He wondered how Khalila would fare with it, but he needn’t have worried; she shouldered it just as easily as the much more muscular Glain. Only Izumi, the smallest of them, seemed overwhelmed, but she didn’t complain.

‘Watch out for each other,’ Wolfe said, when they were all ready. ‘This will not get any easier, I can promise you. I didn’t want you involved in this, but since you are, I need all of you focused. Follow orders without delay, and stay alert.’

It was Wolfe’s concern, Jess thought, that was the most unsettling part of this.

‘I thought we were going to Oxford,’ Thomas said. ‘What are we doing here?’

Wolfe said, ‘You are in the Translation Chamber. That is how we will travel.’

Jess had heard of it, but only in whispers … the same principles that allowed for the mirroring of documents and the movement of books back to the Archive could allow different kinds of things to be physically moved from one spot to another … with the direct participation of an Obscurist. It wasn’t something he’d ever expected to see.

There was a brief hesitation before Dario said, ‘I thought the Translation Chamber was only used to send supplies.’

‘It is,’ Wolfe said. It sounded casual, but Jess wasn’t deceived. ‘But it can also be used to send people in emergencies. I will warn you, it can take years of practice to grow accustomed to Translation; some never do.’

‘We – haven’t had years of practice,’ Thomas said. ‘Or any practice.’

‘I’m aware,’ Wolfe said. ‘But needs must. It’s a simple enough process, one that requires little from you but to clear your mind. If all goes well, you’ll appear in the Translation Chamber in Aylesbury, which is the closest safe point to Oxford.’

‘And if all doesn’t go well?’ Khalila asked.

Wolfe ignored the question. He reached out and pressed his gold band to the matching Library symbol embossed on the far wall, and a hidden door swung open.

On the other side was a dizzying array of wires, tubes … a tangle of metal and harsh lights. So different from everything else Jess had seen here. Massive and intimidating, this … machine, he supposed he should call it. In the centre of it was a clear space, and an old man in a white robe stood with a bronze metal helmet in his hands. The helmet was connected to wires that led into the tubes.

There was a sudden, loud hiss, and white steam billowed up over their heads. Jess ducked. So did everyone, except Wolfe.

Niccolo Santi stepped into the room and edged past them to Wolfe. He had on a pack, too, but his looked well worn. ‘Let me go first,’ he said. ‘Show them how it’s done.’

Wolfe nodded and put his hand on Santi’s shoulder. ‘In bocca al lupo.’

‘In bocca al lupo,’ Santi said, and walked to the centre of the room where the old man was waiting. ‘I’m ready.’

The old man sighed and fitted the helmet down over Santi’s head. It looked tight, and left only a small part of his face showing.

Santi’s easy smile faded, and he closed his eyes. Stood very still.

‘Ready?’ the old man asked. Santi nodded. ‘The connection isn’t good. It will hurt.’

‘Always does. Get on with it.’

The old man put his palsied, unsteady hands on the metal helmet Santi wore.

A column of orange symbols rose up into the air around the two of them, and began to revolve. Slowly at first, and then faster and faster, until it was just a blurring tornado of light. The old man suddenly jerked his hands away, and the light contracted down to a tight, whirling circle around Santi’s body.

The circle drew in on itself into a single, brilliant orange point of light, and Santi … folded. There was a flash of something horrible, something so fast Jess hardly saw it: sprays of blood and torn flesh and the fragments of bones. A powerful wave pushed through Jess’s flesh, and he felt the hair rise on his head and arms in response to something alien, terrifying, and wrong.

The metal helmet fell with a heavy thud to the floor. Empty. Then it was silent. Dead silent.

The Obscurist – he had to be one, there was a golden collar around his throat – staggered backward, breathing heavily.

Khalila let out a choked cry, and pressed both hands to her mouth as if she felt sick. Jess knew exactly how she felt. How were they supposed to endure that?

In the silence, the Codex in Wolfe’s pocket buzzed. He checked it. ‘He’s through,’ he said. ‘Next.’

It was abruptly very real, Jess thought; the pack dragging on his back, the Translation Chamber, the future opening wide and unknown at his feet like an abyss. His feet felt frozen to the spot.

It was somewhat surprising that it was the quiet Guillaume Danton who stepped forward and said, ‘I’ll go.’ He didn’t sound frightened, but Jess caught the telltale tremor of his hands.

Wolfe put a hand on Danton’s shoulder and guided him forward. He picked up the helmet and placed it on the boy’s head. ‘Think about the sky,’ he told him. ‘Close your eyes. Think about the blue sky, and clouds moving over it. White clouds. Moving over a blue sky.’ Wolfe’s voice seemed different now, slow and soothing, and Jess saw Danton’s body actually relax. Wolfe nodded to the Obscurist, who placed his hands on the helmet. ‘Blue sky.’

‘I see it,’ Guillaume said, and smiled.

The orange light formed around him. Symbols swirled. Wolfe took a step back. ‘White clouds,’ he said. ‘Watch them move.’

‘White clouds—’

The light snapped in on itself, and Danton screamed. It was a horrible cry, ripped right out of the core of him, and Jess started forward, but Wolfe was in his way, holding him back.

‘You can’t help him,’ he said.

Jess stared as Danton’s body was ripped apart, folded, gone. The horrified shrieking cut off clean, and that wave of power flashed over his skin like a burn.

The empty helmet clattered to the floor.

Wolfe checked his Codex. Something changed in his expression, just a brief flash: anger, anguish, fury – hard to know. He said, ‘Next.’