As they hurried down the dark corridor, Irene pondered the likelihood of them getting stopped by guards. She was astonished they’d come as far as they had. True, the Winter Palace must be afflicted by the usual security blind spot, as in ‘the outer walls are well guarded, so anyone inside must belong there’. But even so, given the rumours of rebellion and secession, and the government crackdowns, shouldn’t there be a bit more security inside the palace? The further they went, the more nervous she became. She started to worry that they were actually being lured into some vast trap, and were being drawn well inside so that they’d have no chance of escape . . .

‘Stop right there!’ came an order.

It was almost a relief. Irene obediently stayed where she was, one hand on Kai’s sleeve. Only three guards defended the archive’s doorway, their ultimate goal – good heavens, what on earth were they thinking? Though to be fair, the door behind them did look heavily locked and barred.

‘Approach and identify yourself!’ came the next order.

Perfect. Irene walked forward. Even better, she could see which of the guards was clearly in command. She slipped a hand into her bodice, then withdrew it and showed it to the lead guard, as though she’d just pulled something out that only he should see. ‘You perceive that this is full identification, and that we are authorized to view the contents of this archive,’ she said.

The guard snapped into a terrified salute, his back straight with the rigidity of panic. The other two guards followed suit a moment later. ‘Yes, ma’am,’ he said quickly. ‘Absolutely, ma’am!’

‘You may open the door and assist me,’ Irene said briskly, wondering exactly who he thought she was. Probably Oprichniki. Only secret police get that sort of reaction. ‘Your men will remain outside. There’s no need for them to hear this.’

He nodded and pulled a key from his belt, which he quickly turned in the lock. There was a small noise, almost a sigh, from the door as he pulled it open. Irene suspected there had been some sort of magic alarm on it. Now, just so long as the guard stayed confused until they were inside . . .

They were into the next room, and Kai had closed the door behind them, before the guard shook his head and frowned. But Kai had been expecting that, and had him in a chokehold before he could raise the alarm. Irene left him to throttle the fellow into unconsciousness – there was no need to kill him, after all – and looked around. They were in a small anteroom, with another heavily barred door on the far side. All right, so the security wasn’t that laughable. There were rows of ledgers in bookshelves to one side, presumably with lists of items held in the repository beyond. And there was a little desk, with a woman in heavy robes trying to hide under it.

Irene walked over and leaned on the desk. ‘That’s not actually working, you know,’ she said gently.

The woman pulled herself upright, flinching back against the wall. ‘I won’t help you. I will defend this place with my life!’

Irene nodded understandingly. ‘That’s quite understandable,’ she agreed. ‘But you now perceive that I am someone who has a right to be here, and a right to be given the location of a particular item.’ Her head was starting to ache.

‘Oh.’ The woman stayed pressed against the wall. But she looked a little calmer now, as if Irene was a known and understandable threat, rather than something completely unpredictable. ‘Ah, what item would your excellency wish to see?’

‘A book,’ Irene said, daring to hope. ‘It’s called The Manuscript Found in Saragossa, and it’s by Jan Potocki. Where is it?’

The woman edged from behind her desk, staying on the opposite side to Irene, and hurried over to the ledgers. She pulled one out and leafed through it, muttering to herself. Her heavy embroidered sleeves swung as she turned the pages. She finally came to a stop and rested her finger on an entry. ‘Here it is – wait, who did you say you were again?’

Kai rapped her on the back of her neck and caught her before she could hit the ground, while Irene bent to look at the ledger. It was indeed an entry for the book they wanted, but as Irene read it she blinked in shock. ‘I don’t believe it,’ she said out loud. ‘It was released to the Empress herself two days ago, for personal bedtime reading!’

Kai propped the woman up against her desk. ‘Please tell me you’re joking,’ he said.

‘I wish I were.’ Irene weighed steal book from palace’s underground sanctuary against steal book from imperial bedroom. An imperial bedroom was probably even more heavily guarded than an underground sanctuary. Marvellous. ‘Well, we can’t just stand around here,’ she said with a sigh. ‘Let’s go and try again.’

‘How do you know it was for bedtime reading?’ Kai asked.

‘The lady in question signed it out herself. Apparently she has a sense of humour.’ Not that that was likely to save Kai or Irene’s necks, if they were caught mid-theft. ‘I almost regret accepting the mission now.’

‘Why?’

‘Because I’m quite happy to steal a book from storage where nobody’s ever going to read it,’ Irene explained. ‘But I do feel a bit guilty about snatching it mid-read from someone’s bedside table.’

The guards on the door were only too happy to wave them past, after being told that their commanding officer was checking the security inside. Irene led the way back in the direction from which they’d come. ‘Back up the stairs,’ she murmured, ‘up to the first floor, then we take a run at the bedroom.’