As far as I knew, the flask was still in the pocket of Gideon’s leather jacket, but I didn’t tell Lesley so. “Paul told us at least twenty times we ought to destroy it.”

“And he’s no fool!”

“No!” I shook my head. “Gideon thinks it could turn out to be our trump card.”

“Gross,” said Raphael. “You could always auction it on eBay for a joke. Immortality powder, to be taken once only. Minimum bid one pound.”

“Apart from the count, I don’t know anyone who wants to be immortal,” I said, rather bitterly. “I don’t like the idea of staying alive when everyone else around me will have to die sometime. I’d sooner throw myself off a cliff than be left all alone in the world!” I suppressed another sigh at this idea. “Do you think this immortality thing could be a kind of genetic defect in me? After all, I have not just one time travel line in the family, I have two of them.”

“There could be something in that,” said Lesley. “And the Circle does close with you—in every sense.”

For a while we sat lost in thought, staring at the opposite wall. It had some words in Latin painted on the plaster in black lettering.

“What does that say?” asked Lesley at last. “Don’t forget to fill the fridge?”

“No,” said Raphael. “It’s a quote from Leonardo da Vinci, and the de Villiers family stole it from him to use it as their motto.”

“Then I expect that in English,” said Lesley, “it means something like ‘We’re not just showing off, we really are wonderful.’ Or ‘We know everything, and we’re always right!’”

I giggled.

“‘He who is fixed to a star does not change his mind,’” said Raphael. “That’s what it says.” He cleared his throat. “How about I find some pens and paper? To help us think better?” He grinned awkwardly. “Maybe it’s kind of sick, but I must say I’m enjoying your mysterious game.”

Lesley sat up straight. A smile slowly spread over her face, and the freckles on her nose began to dance. “Me too,” she said. “I mean, I know it’s not really a game, it’s a matter of life and death, but I’ve never had such fun before as these last two weeks.” She cast me an apologetic glance. “Sorry, Gwenny, but it’s megacool to have an immortal time traveler for a friend. Much cooler, I guess, than actually being one.”

I couldn’t help laughing. “You’re right. I’d be having more fun myself if we could change places.”

When Raphael came back with paper and colored pencils, Lesley immediately began drawing little boxes and arrows. “It’s that stuff about an accomplice of the count among the Guardians that really gives me a headache.” She chewed the end of her pencil for a moment. “Although that’s only an assumption in itself, but never mind. Basically, it could be anyone, right? The minister of health, that weirdo the doctor, nice Mr. George, Mr. Whitman, Falk … or that red-headed idiot, what’s his name again?”

“Marley,” I said. “But I don’t think he’s the type for that kind of thing.”

“He’s descended from Rakoczy, all the same. And it’s always the least likely person who did the deed, you know it is!”

“Right,” agreed Raphael. “The ones who seem harmless are usually the villains. You want to be particularly careful with idiots who stutter.”

“This accomplice of the count’s, let’s call him Mr. X for now, could have been the murderer of Gwenny’s grandfather.” Lesley scribbled busily on her piece of paper. “And he would probably have been the one told to kill off Gwenny once the count had his elixir.” She gave me a loving look. “At least I’ve been a tiny little bit less worried about that since I’ve known you’re immortal.”

“Immortal, but not invulnerable,” said Gideon. We all jumped and looked at him in surprise. He’d come into the apartment unnoticed and was now leaning in the doorway with his arms folded. He was still wearing his eighteenth-century outfit, and as always, my heart did a painful little thump at the sight of him.

“How’s Charlotte?” I asked, hoping the question sounded as neutral as I’d intended.

Gideon wearily shrugged his shoulders. “I guess she’ll have to take a few aspirins tomorrow morning.” He came closer. “What are you all doing?”

“Making plans.” Lesley had her tongue wedged in the corner of her mouth as her pencil moved fast over the paper. “And we mustn’t forget the magic of the raven,” she added, more to herself than anyone else.

“Gid, who do you think the count’s secret accomplice among the Guardians could be?” Raphael was biting his nails. “I suspect Uncle Falk. I always thought he was very odd, even when I was little.”

“Nonsense.” Gideon came over to me and dropped a kiss on my hair before plopping into the well-worn leather armchair opposite. He propped his elbows on his knees and put a strand of hair back from his face. “I can’t get what Lucy said just now out of my mind. About the count losing his immortality from the moment when Gwyneth was born.”

Lesley tore herself away from her diagrams and nodded. “But beware: when the twelfth star shows its own force, His life here on earth runs its natural course,” she quoted, and I was annoyed, yet again, to find that the silly jingle could send a shiver down my spine. “And if youth is destroyed, then the oak tree will stand, To the end of all time, rooted fast in the land.”

“Do you know all that stuff by heart?” asked Raphael.

“Not all of it. But many of those verses sort of stick in the mind,” said Lesley, slightly embarrassed. Then she turned to Gideon. “This is how I see it. If the count swallows that powder in the past, he becomes immortal. But only until the twelfth star rises, meaning … er … until Gwyneth is born. Then it’s good-bye to his immortality; he’ll age like anyone else. Unless he kills Gwyneth to stop the process in its tracks. But before that, she has to make it possible for him to get hold of the elixir in the first place. And if he never gets the elixir, he won’t get to be immortal either. Am I making sense?”

“Sort of,” I said, thinking of Paul and the subway systems being built in our brains.

Gideon slowly shook his head. “But suppose we’ve been making a mistake all along in our reasoning?” he asked thoughtfully. “Suppose the count got his hands on the powder long ago?”

I almost said, “What?” again, but I managed to stop myself just in time.

“That’s not possible, because in one of the chronographs the Circle of Blood still hasn’t been closed, and I hope the elixir from the other is hidden somewhere safe.”

“Yes,” said Gideon, still slowly. “Yes, right at this minute it is. But it doesn’t necessarily have to stay that way.” He sighed as he saw our blank expressions. “Think about it: it’s possible that at some point in the eighteenth century, the count—by one means or another—did take the elixir, and it made him immortal.”

All three of us stared at him. I came out in goose bumps all over, without really knowing why.

“Which in turn would mean that he may be alive at this very moment,” Gideon went on, looking me straight in the eye. “He could be going around out there somewhere, just waiting for us to take the elixir back to him in the eighteenth century. And then looking for his chance to kill you, Gwyneth.”

For a few seconds, silence reigned. Then Lesley said, “I don’t say I entirely follow you, but even if for some reason you two change your minds and you do take the count the elixir … wouldn’t he have one tiny problem?” At this point she laughed happily. “He can’t kill Gwenny.”

Raphael made his pencil spin on the table like a top. “And anyway, why would you change your minds, now that you know the count’s real intentions?”

Gideon didn’t answer at once, and his face was almost expressionless as he finally said, “Because we could be blackmailed.”

* * *

I WOKE FEELING something damp and cold on my face, and Xemerius said, “Your alarm clock will go off in ten minutes’ time!”

Groaning, I pulled the quilt up over my head.

“There’s no satisfying you! Yesterday you complained because I didn’t wake you.” I seemed to have hurt Xemerius’s feelings.

“I hadn’t set my alarm clock yesterday. And it’s horribly early,” I muttered.

“You have to make a few sacrifices if you want to save the world from an immortal megalomaniac,” said Xemerius. I could hear him humming as he flew around the room. “The megalomaniac you’re due to meet this afternoon, in case you’d forgotten. Come on, rise and shine.”

I played dead. Which wasn’t very difficult, because immortal or not, I felt just about dead. However, Xemerius didn’t seem much impressed by my efforts. He fluttered cheerfully up and down in front of my bed, churning out old wives’ sayings along the lines of the early bird catches the worm.

“The early bird’s welcome to all the worms it likes,” I said, but in the end, Xemerius got his way. Irritated, I rolled out of bed, and as a result, I was at the Temple Tube station on the dot of seven in the morning.

Well, strictly speaking, it was seven sixteen, but the time on my mobile was a little fast.

“You look as tired as I feel,” groaned Lesley, who was already waiting for me on the platform where we’d agreed to meet. There wasn’t much going on in the station at that time of a Sunday morning, but I wondered how Gideon expected to get into one of the underground tunnels from here unnoticed. The platforms were brightly lit, and the place was full of CCTV cameras.

I put down my heavy traveling bag, which was packed full of stuff, and cast a sour glance at Xemerius, who was flying in and out between the columns in a headlong slalom race. “It’s Xemerius’s fault. He wouldn’t let me use Mum’s concealer because he said it was so late. And he wouldn’t let me stop off at a Starbucks on the way here either.”

Lesley put her head on one side, with an interested look. “You slept at home?”

“Yes, of course, where else?” I asked rather impatiently.

“Well, I thought the pair of you might have taken a break from making plans after Raphael and I left.” She rubbed her nose. “Particularly as I spent ages saying good night to Raphael, on purpose to give you time to move from the sofa to the bedroom.”

“On purpose?” I asked slowly. “Wow, how self-sacrificing of you!”

Lesley grinned. “Yes, wasn’t it?” She didn’t even blush. “But don’t change the subject. You could have told your mum you were sleeping over with me.”

I smiled wryly. “To be honest, I’d have done just that. But Gideon insisted on calling a taxi for me.” I added, a little unhappily, “I obviously can’t have looked as seductive as I thought.”