For most of the journey to Snagov I just shut my eyes and tried not to think of the perilous cliffs that fell away into darkness on either side as we sped through the night. The only trouble was that every time I closed my eyes, all I could see was the outline of the Beast, writhing its tentacles (or whatever they were) in the air, and glaring at me with blood-red eyes.

It meant I was pretty happy when we finally screeched to a stop on the outskirts of the little town of Snagov. It was still dark, but I could see Bella glancing at the sky a couple of times. Dawn could not be that far off. The sooner we reached the cave and got under cover the better – before Bella got hit by the sun. And yes, I knew this meant we’d be closer to the Beast – but we’d also, I hoped, be closer to rescuing Henry.

Bella throttled the engine to a quieter level and wove her way quickly through the deserted narrow streets dotted with small red-roofed houses until we were out on the main road again. We passed the ruins of what must have once been a monastery, and I remembered again that Snagov was where Bella’s father – Count Dracula – was buried. I glanced at Bella – she was staring at the ruins with a strange look in her eyes. I supposed that even a five-hundred-year-old person must feel a bit sad near the grave of one of their parents – even if he was Vlad the Impaler.

The winding track led up into a range of mountains, growing steeper all the way. After a while even Bella’s motorbike began to sound breathless, and as the terrain became too uneven for the bike’s tyres, she pulled over to the side of the road.

“We’ll walk from here,” she said, dismounting. As soon as I’d jumped off she hid the bike in a thick strand of bushes. I hoped we’d be able to find it again on the way back.

That’s if we ever did come back.

We pressed on by foot, climbing always higher, scrambling over rough slopes. Having had very little sleep, I was struggling with exhaustion at this point, and several times I slipped. But Bella was looking out for me at every turn it seemed, and would grip my arm to stop me falling down the mountainside. I realised that she could probably travel a lot more quickly than me – I was holding her up. But when I tried to suggest that she go on ahead of me she simply shook her head and continued to climb.

Finally she stopped. We’d arrived at a place where the rocks formed a natural shelf, and there before us was a narrow opening leading into darkness.

I remembered the words cast by the Transylvanian glass, back in Whitby:

“What’s this place called?” I asked, pretty much knowing what the answer would be.

As if she had read my mind, Bella spoke. “In English, this place is called the Mountain of the Worm.” Then she held her finger to her lips, as if listening.

All I could hear, other than the wind, was my heart hammering.

“There are at least twenty people inside – maybe more,” she said eventually.

“Can you hear Henry?”

She listened again. “No, I can’t hear his voice. That doesn’t mean he’s not in there,” she added as my shoulders slumped. “He may be asleep, or unconscious, or simply out of range. Even my hearing has its limits.”

I didn’t much like the idea of Henry being unconscious, but I knew it was a possibility. We had to go in.

“We’d better get moving then,” I said, heading towards the dark opening.

Bella held me back by the arm. “So impulsive! We need to go quietly. Try to make your big feet tread as softly as you can.”

I tried not to look hurt. My feet aren’t that large, though I suppose if you’re a silent-stepping vampire all humans make a lot of noise. So I followed Bella into the crack in the rocks as quietly as I could, trying to remember all of Henry’s lessons in surveillance – putting the weight on the balls of my feet rather than the heels, trying to breathe as quietly as possible.

We found ourselves in a high, narrow passage that looked as if someone had used a pickaxe to widen it. There was really only enough room for one person at a time, so we went in single file. A few minutes later we emerged into a much larger, darker space. I reached for my torch, about to flick the switch, when Bella knocked my hand aside.

“Do you want to tell the whole world we’re here?” she hissed. “Silly boy! I can see well enough. Just stay close and I’ll make sure you don’t fall into any holes.”

I was angry at myself for being so stupid, and began to follow Bella blindly, knowing only that I was in the middle of a cavern of some kind. The darkness pressed in on me like a thick curtain. Every sound we made (or should I say I made?) seemed to be magnified in the otherwise silent cave. But finally I began to hear other sounds – a kind of hollow booming – that I gradually realised was the voices of people echoing back from the cavernous walls.

They were chanting something. And although I couldn’t hear what it was, there was an ominous quality to it that spooked me. By now, some light was visible, and I no longer had to rely solely on Bella to guide me. The light got stronger, until we arrived at the entrance to another cave and brightness poured out from it, along with the sounds of chanting. And then the sound stopped. We heard a voice calling for silence.

Bella pressed a finger to her lips and laid down on her front, signalling for me to do the same.

We inched our way forward on our elbows until we could see into the cave. It was a smallish cavern and brightly lit by dozens of burning torches stuck into holes around the walls. The smoke rising from them gave everything a wavering quality that made the scene all the weirder.

There were maybe sixty people in there, and I remember thinking at the time that they’d all obviously been watching too many horror movies because they were dressed in long dark robes with hoods. I recognised the medallions they had around their necks – the same as the one Bella had shown me at her house. They were gathered in front of a big rock that formed a natural platform, on which stood a figure in a red robe – I suppose so you could tell he was the boss. He had his hood pulled down so I couldn’t see his face, but there was something unsettlingly familiar about his voice.

“My friends,” he said, “I speak to you in English because there are many here who have come from afar and do not know our tongue. The time has almost come when our work will be complete. The Great One will arise! He will make us all immortal! Then, we shall take our places in the world as leaders, as conquerors!”

His words didn’t surprise me. Why is it these types always want to conquer everything? I mean, if they actually got all the power, what would they do with it?

Meanwhile, there was a lot of chanting of “The Great One! He arises!” and that sort of thing. They sounded a bit like a football crowd, albeit an echoey one.

The hooded leader held up his hands. “Tonight we shall offer an interloper to the Great One. This offering will be the means of his awakening. His gratitude will be such that he will reward us all! The Order of the Dragon will be triumphant!”

So that was who they were. As Henry had told me, Dracula himself, Vlad Tepes, had belonged to an Order of the Dragon, back in the Middle Ages. But I thought that had been a kind of Knights of the Round Table thing, with a lot of blokes running about waving swords. What were these people doing here now?

They were all still chanting, but I had stopped listening. I had a nasty feeling that by ‘interloper’ the hooded guy meant Henry, and judging by Bella’s expression she had reached the same conclusion. She pointed backwards and we withdrew from the cavern.

As soon as I thought it was safe to speak I whispered, “They mean Henry, don’t they?”

Bella nodded grimly.

“And they’re going to feed him to the beast thing, aren’t they?”

“I’m afraid you may be right,” she said in a very low voice.

“So what can we do?”

“We must see if we can discover where they are holding him. Then we will decide what to do.”

I was glad that Bella was taking charge – she seemed so decisive – but before I could say anything more my ears were hit by a sudden outburst of shouting from the cave. We crawled back to our viewpoint and stared down at the scene.

“Well,” I murmured – the noise in the cave would no doubt cover up anything I said – “at least we don’t have to go looking for him now.”

There, looking a bit dazed, was Henry – held on the platform by two large men in robes. I recognised the expression on his face – curiosity. Whereas most people in HH’s situation would give in to fear, Henry was fascinated by everything going on around him.

At the sight of my friend, I was overwhelmed with both relief and concern that the worst might be yet to come.

The leader held up his hands for silence again.

“My friends,” he bellowed, “the moment for which we have worked so long is almost upon us. Soon the Great One shall awaken, and this foolish enemy shall be the first to feel his anger and the first one upon whom he will feast.”

Henry’s eyes were darting about, probably looking for a way to escape, while everyone started shouting and cheering and jumping about again. The man on the platform pushed back the hood of his scarlet robe and spread his arms wide as if to embrace his followers.

Now I realised why his voice had seemed familiar.

It was Mr Antonescu.

As I stared at our ‘guide’ I got that funny, empty feeling in the pit of my stomach – you know, the kind of feeling you get when you’ve just heard that your best friend got eaten by a tiger. I looked at Bella.

For a second longer she stared at Mr Antonescu, who was still directing the chants and cries of “The Great One!” like a conductor in an orchestra, then she snorted. “There is no time for this. We must rescue your friend.”

I was desperate to do the exact same thing, but as I looked at the crowd in the cavern – who all looked decidedly crazed – and the two hulking guys holding Henry, I didn’t have much of an idea how to go about it.

Fortunately, Bella did.

“This is going to look a little weird,” she warned, and before I could ask what she meant she began to change.

Her form wavered, right there before my eyes. For a moment she became transparent so that I could see the cavern through her, then she faded out entirely. In place of Bella was a plume of green-grey smoke, which began to drift away across the cavern over the heads of the chanting group. At the same time I heard, like an echo that was somehow inside my head, “Stay there. Be ready to run!” It was Bella.

To be honest, I’m not sure what else I could have done. Gone charging into the cave full of sweaty people in robes in the vague hope of not getting killed before I got to Henry? I don’t think so!

So I stayed, watching and hoping. And, believe me, what happened then was pretty amazing.

The plume of smoke that was Bella hovered for a minute over the head of Mr Antonescu, then descended onto the platform where the two hulking guys were holding on to Henry. The smoke suddenly grew still and, just as she had disappeared, there was Bella, solid and real. Everyone froze. The mob stopped cheering and stared. Bella, on the other hand, flowed into action right away. She grabbed the two big guys who were holding Henry and tossed them aside as if they weighed nothing.

As they flew through the air Bella picked Henry up. She flung him over her shoulder like a sack of potatoes and jumped back down – right into the middle of the mob.

But the robed group had recovered from their surprise and launched into a full attack as soon as Bella landed. I’ve seen some pretty cool moves, although mostly on a film screen (well, who doesn’t love a bit of kung fu?), but nothing compared to this. Bella went through the mob like the hero of an action movie. A couple of them managed to land blows on her, but considering she was carrying Henry as well, most of them looked like they were made of cardboard. It helped, of course, that Bella was in full vampire mode by then, her face dead white except for her lips which had turned a deep red, her blue eyes glaring like searchlights.

There were shouts of “Dracula” and “Nosferatu” (which Henry had already told me was the Rumanian for ‘vampire’) and all of a sudden the crowd drew back. Only Mr Antonescu seemed to be unaffected. He still stood on his platform, his face a mask of rage – far from the rather gloomy, uncommunicative fellow of earlier.

“She is a traitor, an enemy of the Beast,” he shouted above the din. “Destroy her!

Meanwhile Bella had climbed like lightning up to my hiding place, where she dumped Henry unceremoniously on his feet.

“You okay?” I asked Henry.

“Just about,” he answered, swaying a bit. “Good to see you, Dolf – and you, Miss Dracul…”

Before the tide of Snagov worshippers could chase her down, she turned and advanced on them. It was clear they still weren’t sure which of them wanted to be the first to feel Bella’s wrath – or her teeth – and they recoiled, backing off towards the platform, and their leader.

But at this Mr Antonescu’s face became even darker with anger. “Death to the traitor!” he screamed.

Like sheep, the mob moved back again in our direction. They were obviously more in fear of their leader than they were of vampires.

“Time to go,” said Bella quietly. “Follow me.”

She took off at a sprint down the tunnel. Henry and I followed – though I could tell that he was still a bit unsteady on his feet from the way he kept tripping and skidding on the uneven ground. But he kept going somehow, though we had a hard time keeping up with Bella until I yelled, “Slow down a bit. We aren’t vampires!”

It was pretty dark in the tunnel once the light from the cave had faded, and once again I had to rely on Bella. She led us off down a side passage which then branched several times. I guessed she was trying to lose our pursuers by taking turns they wouldn’t even see. Finally she stopped so suddenly that Henry ran right into her.

“Where are we going?” he puffed.

“Away from those unpleasant people,” Bella answered curtly.

“But who exactly are they?” I put in.

“An ancient society who worships the Beast,” Bella said. “That much is clear.” She looked around. “We should go further away from here. They are angry and will not give up until they have caught us.”

I could hear distant shouts and cries – Bella was right.

“Well, let them try!” said Henry fiercely. “I can show them a thing or two.”

“Where shall we go?” I asked, keen to get out of the mob’s way, no matter how many martial arts Henry was trained in. “Back outside or further in?”

“Further in is best,” Bella said. “They will not expect us to go this way and besides…” She hesitated. “I think the only way to end this is to find the Beast…”

I have to admit my heart sank. As if we weren’t in enough trouble already, Bella was suggesting we go right into the lair of the Snagov Beast. It was fine for her – she couldn’t be killed easily. I had a feeling we wouldn’t be so lucky.

But I wasn’t surprised at Henry’s reaction. “That’s the best idea I’ve heard all day,” he said, nodding.

I could have been wrong but I thought I could see Bella smiling in the darkness.

“Follow me,” she said.