‘But Pyotr lived!’ said Aleksei. ‘For another thirteen years.’

‘He certainly did,’ said Aleksandr. ‘Pyotr was far more cunning than anyone gave him credit for. Do you know what he’d been doing in those three days he had asked Zmyeevich to wait? He had been eating: rare beef, venison, liver – kishka especially. Anything to build up the blood. He’d known he was taking a risk, that Zmyeevich might still take enough blood to kill him, but Pyotr was always a gambler. They took him straight to his bed, and he was there for almost three weeks. They fed him on the same sorts of things. He had no appetite, but he knew he must do it to live. Before long, he was as healthy as he had ever been.’

‘But why go to all that risk?’ asked Wylie.

‘For the enlightenment that Zmyeevich had promised him. He claimed that in those few moments, as the monster fed on him, he could see the whole world. He saw the future of Russia – an illustrious future. The knowledge faded quickly, but he remembered a little of it, enough to make his country a great one. Perhaps if he had completed the process it would have stayed for ever – but at what cost? Later in his life, he occasionally saw images in his mind that he knew must come from Zmyeevich – as do I. I saw you through his eyes, Aleksei Ivanovich, briefly, when he met you in 1812. Though why you were with him, I still do not know. Perhaps one day you will tell me.’

‘And did he call on the other generations of Romanovs?’ asked Wylie.

Aleksandr shook his head. ‘Not all. Or perhaps he did, but they kept it to themselves if so. He certainly visited my grandfather, Pyotr III. Convinced him too.’

‘To become a vampire?’ asked Wylie, astounded.

‘That’s what Yekaterina told me – and that’s why she overthrew him, though she had plenty of other reasons. But she wasn’t a Romanov, you see, so she was… immune. When Zmyeevich came back to take his prize, he learned that the tsar was dead. Yekaterina was waiting to confront him. He knew he wouldn’t get anywhere while she was alive, but he had time to wait. He was not confined to a single generation.’

‘But hang on,’ interrupted Tarasov. ‘You – and your grandfather – are descended from Pyotr by his daughter Anna Pyetrovna.’ The tsar nodded. ‘But she was born in 1708, before any of this happened. How could this… infection be carried to you by her?’

‘It’s not an infection,’ explained Aleksandr. ‘Zmyeevich took Pyotr’s blood, not the other way round. Pyotr’s blood was Romanov blood, as was Anna Pyetrovna’s – as is mine. It doesn’t matter if it was taken before or after she was conceived.’

‘Contagious magic,’ muttered Tarasov.

The tsar nodded. ‘That would seem to be the term for it.’

‘Yekaterina told you all this?’ asked Aleksei.

‘Some of it. Cain told me more. He was quite keen that I understood what was to happen to me. He claims to understand much more of it than Zmyeevich.’

‘I bet he does,’ said Aleksei.

‘So what happened – in the cave with Cain?’ asked Wylie.

‘He had a vial of Zmyeevich’s blood. He offered it to me. All I had to do was drink it. Then death for me would not be an ending, but a transformation. I would rise again, a new creature, wiser, stronger, more powerful than I had ever been before. I would live for ever.’

‘Just as Zmyeevich promised your great-great-grandfather,’ said Aleksei.

‘Yes, but babushka had warned me. I would get all those things, but I would become completely subservient to Zmyeevich. Russia would still be mine, but I would be his. Cain confirmed it. They were going to take me away, back to Zmyeevich’s country, but then I’d return and rule Russia. Someone would eventually understand that all wasn’t right, but by then, Zmyeevich hoped, it would be too late; he would have taken his grip on power.’

‘And when you refused, that was when he decided to kill you,’ said Aleksei. ‘I must have arrived just in time.’

‘Oh, no,’ said Aleksandr. ‘My refusal meant nothing to him. He told me I had no say in the matter.’

‘But I thought a man could only become a vampire willingly.’

‘That’s what Zmyeevich thought – and why he waited so long. Cain believed it at first, but he wasn’t going to be fool enough to take Zmyeevich’s word. He experimented. It turns out the victim does have to be willing – and that in this case, he was.’

‘You were happy to become a voordalak?’ gasped Aleksei.

‘No,’ said Aleksandr. ‘The free will does not come in drinking the vampire’s blood. It comes in allowing one’s own blood to be drunk. Pyotr did that quite happily, and his acquiescence is – apparently – good enough for all of us.’

‘Not quite all of you, I think,’ said Wylie, with half a smile.

‘What do you mean?’ asked the tsar.

‘Something in Cain’s notebook,’ explained the doctor. ‘I didn’t understand it at the time, but now it makes more sense. It said something like, “In each generation, the blood can exert its influence on only one sibling. Whichever is first touched, the others become free.” Once Zmyeevich exerted his power over you, he lost any chance of doing the same to your brothers or sisters.’

‘My brothers, safe?’ said the tsar joyously, despite his weakness, and sitting up a little. ‘Konstantin, Nikolai, Mihail – all of them?’

‘So it would seem,’ said Aleksei, ‘though I wonder how Cain knew.’

‘He didn’t write that down,’ said Wylie.

‘He didn’t shy from experimenting on humans,’ said Aleksei. ‘Why not an entire family?’ He tried to force the image from his mind as he spoke.

‘He’s been planning this for a long time,’ said Aleksandr. ‘Not as long as Zmyeevich, obviously, but this isn’t the first time I’ve encountered him. That was during the Patriotic War.’

‘In 1812?’ Aleksei failed to hide his astonishment.

The tsar nodded. ‘At the very time of Bonaparte’s occupation of Moscow. I was in the capital. He came and offered me much the same arrangement. Back then, he thought I needed to be in agreement, but on the other hand, our country was in direst need. He said Bonaparte would be no match for Zmyeevich and me if we stood together. He even claimed that Zmyeevich was already working to liberate Moscow from the French yoke.’

Aleksei glanced at the other two men, but realized that no one in the room but himself could know what had really happened in Moscow. It was a surprise to him that Iuda had been to Petersburg in that time, but it was perfectly reasonable. Aleksei had spent most of the five weeks of Bonaparte’s occupation of the old capital hiding in Yuryev-Polsky. He had assumed that Iuda had remained in Moscow, but why should he have? There would have been plenty of time for him to travel to Petersburg, spend several days there, and return. His visit to Aleksandr would have taken only a fraction of that time. But all that was history. Aleksei’s concerns now were for the present, and for the tsar.

‘You’re safe now,’ he said. ‘Neither Cain nor Zmyeevich will get to you while we’re here.’

‘Safe?’ wailed the tsar. ‘How can I ever be safe? Even in death I can seek no protection.’

‘Don’t say such things, Your Majesty,’ said Tarasov.

‘Believe me, I would gladly ask you to kill me now if it would free me of this curse, but it will not. To die would be to bring about all that Zmyeevich desires.’

‘What do you mean?’

‘I have drunk his blood,’ said Aleksandr, his lips articulating precisely, though only the slightest of sounds escaped his throat.

‘What?’ exclaimed Tarasov, but it was just as Aleksei had suspected.

‘At Chufut Kalye – he gave me wine. I didn’t think. I didn’t understand – not then. I just drank it. When Cain offered me Zmyeevich’s blood, he was toying with me. I had already drunk it. It’s in me. The blood has been exchanged both ways, and there is only one further step before I come to be like him.’

‘One step?’

‘I must die. You’re right, Aleksei Ivanovich, Cain was about to kill me when you interrupted us, but it was no act of petty vengeance. The blood had been exchanged – that is the purpose of the vampire’s bite, but death itself does not have to be caused by that bite. He wanted to stab me, but I could be poisoned, fall ill. I could have been like that poor fellow Maskov and fallen from my carriage. Cowards die many times before their deaths, but I must truly be afraid to die, for when death comes it will bring for me so awful a resurrection that I cannot bear even to think of it.’