THE DOORS to the Hall of Princes could only be opened by a Prince, by laying a hand on the doors or touching a panel on the thrones inside the Hall. Nothing could breach the walls of the Hall, which had been built by Mr. Tiny and his Little People centuries before.

The Stone of Blood was housed in the Hall, and was of vital importance. It was a magical artefact. Any vampire who came to the mountain (most of the three thousand vampires in the world had made the trek at least once) laid their hands on the Stone and let it absorb some of their blood. The Stone could then be used to track that vampire down. So, if Mr. Crepsley wanted to know where Arrow was, he had only to lay his hands on the Stone and think about him, and within seconds he'd have a fix on the Prince. Or, if he thought of an area, the Stone would tell him how many vampires were there.

I couldn't use the Stone of Blood to search for others - only full-vampires were able to do that - but I could be traced through it, since it had taken blood from me when I became a Prince.

If the Stone ever fell into the hands of the vampaneze, they could use it to track down all the vampires who'd bonded with it. Hiding from them would be impossible. They'd annihilate us. Because of this danger, some vampires wanted to destroy the Stone of Blood - but there was a legend that it could save us in our hour of greatest need.

I was thinking about all this while Paris used the Stone of Blood to manoeuvre troops in the field. As reports reached us of vampaneze positions, Paris used the Stone to check where his Generals were, then communicated telepathically with them, giving them orders to move from place to place. It was this which drained him so deeply. Others could have used the Stone, but as a Prince, Paris's word was law, and it was quicker for him to deliver the orders himself.

While Paris focused on the Stone, Mr. Crepsley and me spent much of our time putting field reports together and building up a clear picture of the movements of the vampaneze. Many other Generals were also doing this, but it was our job to take their findings, sort through them, pick out the more important nuggets, and make suggestions to Paris. We had loads of maps, with pins stuck in to mark the positions of vampires and vampaneze.

Mr. Crepsley had been intently studying a map for ten minutes, and he looked worried. "Have you seen this?" he asked eventually, summoning me over.

I stared at the map. There were three yellow flags and two red flags stuck close together around a city. We used five main colours to keep track of things. Blue flags for vampires. Yellow for vampaneze. Green for vampaneze strongholds - cities and towns which they defended like bases. White flags were stuck in places where we'd won fights. Red flags where we'd lost.

"What am I looking for?" I asked, staring at the yellow and red flags. My eyes were bleary from lack of sleep and too much concentrating on maps and poorly scrawled reports.

"The name of the city," Mr. Crepsley said, running a fingernail over it.

The name meant nothing to me at first. Then my head cleared. "That's your original home," I muttered. It was the city where Mr. Crepsley had lived when he was human. Twelve years ago, he'd returned, taking me and Evra Von - a snake-boy from the Cirque Du Freak - with him, to stop a mad vampaneze called Murlough, who'd gone on a killing spree.

"Find the reports," Mr. Crepsley said. There was a number on each flag, linking it to reports in our files, so we knew exactly what each flag represented. After a few minutes, I found the relevant sheets of paper and quickly scanned them.

"Of the vampaneze seen there," I muttered, "two were heading into the city. The other was leaving. The first red flag's from a year ago - four Generals were killed in a large clash with several vampaneze."

"And the second red flag marks the spot where Staffen Irve lost two of his men," Mr. Crepsley said. "It was when I was adding this flag to the map that I noticed the degree of activity around the city."

"Do you think it means anything?" I asked. It was unusual for so many vampaneze to be sighted in one location.

"I am not sure," he said. "The vampaneze may have made a base there, but I do not see why - it is out of the way of their other strongholds."

"We could send someone to check," I suggested.

He considered that, then shook his head. "We have already lost too many Generals there. It is not a strategically important site. Best to leave it alone."

Mr. Crepsley rubbed the long scar which divided the flesh on the left side of his face and went on staring at the map. He'd cut his orange crop of hair tighter than usual - most vampires were cutting their hair short, because of the ticks - and he looked almost bald in the strong light of the Hall.

"It bothers you, doesn't it?" I noted.

He nodded. "If they have set up a base, they must be feeding on the humans. I still consider it home, and I do not like to think of my spiritual neighbours and relations suffering at the hands of the vampaneze."

"We could send in a team to flush them out."

He sighed. "That would not be fitting. I would be putting personal considerations before the welfare of the clan. If I ever get out in the field, I shall check on the situation myself, but there is no need to send others."

"What are the odds on you and me ever getting out of here?" I asked wryly. I didn't enjoy fighting, but after six years cooped up inside the mountain, I'd have given my fingernails for a few nights out in the open, even if it meant taking on a dozen vampaneze single-handed.

"The way things stand - poor," Mr. Crepsley admitted. "I think we will be stuck here until the end of the war. If one of the other Princes suffers a serious injury and withdraws from battle, we might have to replace him. Otherwise..." He drummed his fingers on the map and grimaced.

"You don't have to stay," I said quietly. "There are plenty of others who could guide me."

He barked a laugh. "There are plenty who would steer you," he agreed, "but how many would clip you around the ear if you made an error?"

"Not many," I chuckled.

"They think of you as a Prince," he said, "whereas I still think of you first and foremost as a meddlesome little brat with a penchant for stealing spiders."

"Charming!" I huffed. I knew he was kidding - Mr. Crepsley always treated me with the respect my position deserved - but there was some truth to his teasing. There was a special bond between Mr. Crepsley and me, like between a father and son. He could say things to me that no other vampire would dare. I'd be lost without him.

Placing the map of Mr. Crepsley's former home to one side, we returned to the more important business of the night, little dreaming of the events which would eventually lead us back to the city of Mr. Crepsley's youth, or the awful confrontation with evil that awaited us there.