Shadowing Mr. Crepsley wasn't easy. The first night we lost him after a couple of minutes: he shot up a fire escape and by the time we got to the top he was nowhere to be seen. We wandered around the city for a few hours, hoping to stumble upon him, but saw neither hide nor hair of him for the rest of the night.

We learned from that experience. While Mr. Crepsley slept the next day, I went and bought a couple of cell phones. Evra and me tested them out before dusk, and they worked pretty well.

That night, when Mr. Crepsley headed for the rooftops, Evra stuck to the ground. He couldn't move as fast as me. By myself, I was able to keep track of the vampire and pass the information to Evra, who followed on the ground.

Even alone, it was difficult to keep up. Mr. Crepsley could move a lot quicker than me. Fortunately, he had no idea I was after him, so he didn't go as fast as he could, since he didn't think he had any need to.

I kept him in sight for three hours that night before losing him when he slipped down to street level and took a couple of turns that I missed. The next night I stuck with him until dawn. It varied after that: some nights I'd lose him within an hour; others I'd be on his tail until morning.

He didn't do much while I was following him. Sometimes he'd stop in one place for a long time above crowds of people and observe them silently (picking out his next victim?). Other times he roamed without stopping. His routes were unpredictable: he might go the same way two or three nights in a row, or try entirely new directions every night. It was impossible to anticipate his moves.

Evra was exhausted at the end of each night - I kept forgetting he wasn't as powerful as me - but he never complained. I said he could stay in for a few nights if he wanted, but he shook his head and insisted on coming with me.

Maybe he thought I'd kill Mr. Crepsley if he wasn't around.

Maybe he was right.

No fresh bodies had been discovered since news of the six in the building broke. It had been confirmed that all the bodies had been drained of their blood, and that they were ordinary humans: two men and four women. All were young - the oldest was twenty-seven - and from different parts of the city.

Evra's disappointment was evident when he heard the victims were normal people - it would have made life much easier if they'd been vampires.

"Would doctors be able to tell the difference between a human and a vampire?" he asked.

"Of course," I replied.

"How?"

"Different kind of blood," I said.

"But they were drained of blood," he reminded me.

"Their cells wouldn't be the same. Atoms act strangely in vampires - that's why they can't be photographed. And they'd have extra-tough nails and teeth. The doctors would know, Evra."

I was trying to keep an open mind. Mr. Crepsley hadn't killed anyone while we'd been following him, which was a good sign. On the other hand, maybe he was waiting for the fuss to die down before striking again - at the moment, if somebody was late home from school or work, alarm bells rang immediately.

Or perhaps he had killed. Maybe he knew we were following him and was only killing when he was cer-tain he'd lost us. That was unlikely, but I didn't rule it out completely. Mr. Crepsley could be crafty when he wanted. I wouldn't have put anything past him.

Although I was sleeping through most of the days - in order to stay awake at night - I made a point of waking a couple of hours before sunset to spend some time with Debbie. Usually I went over to her house and we sat upstairs in her bedroom and played music and talked - I was always trying to conserve energy for the night chase ahead - but sometimes we'd go for a walk or hit the stores.

I was determined not to let Mr. Crepsley ruin my friendship with Debbie. I loved being with her. She was my first girlfriend. I knew we'd have to break up sooner rather than later - I hadn't forgotten what I was - but I wouldn't do anything to shorten our time together. I'd given up my nights to pursue Mr. Crepsley. I wasn't going to give up my days, too.

"How come you don't come around after dark anymore?" she asked one Saturday as we came out of a matinee. I'd woken up earlier than usual so that I could spend the day with her.

"I'm afraid of the dark," I whimpered.

"Seriously," she said, pinching my arm.

"My dad doesn't like me going out at night," I lied. "He feels a little guilty, not being around during the day. He likes Evra and me to sit with him at night and tell him what we've been up to."

"I'm sure he wouldn't mind if you went out now and then," Debbie protested. "He let you out the night of our first date, didn't he?"

I shook my head. "I snuck out," I said. "He went crazy when he found out. Wouldn't speak to me for a week. That's why I haven't introduced you to him - he's still fuming."

"He sounds like a mean old man," Debbie said.

"He is." I sighed. "But what can I do? He's my dad. I have to stick by him."

I felt bad lying to her, but I could hardly tell her the truth. I smiled to myself when I imagined breaking the news: "That guy I say is my father? He's not. He's a vampire. Oh, and I think he's the one who killed those six people."

"What are you smiling at?" Debbie asked.

"Nothing," I said quickly, wiping the smile from my face.

It was a strange double life - normal boy by day, deadly vampire-tracker by night - but I was enjoying it. If it had been a year or so earlier, I would have been confused; I would have tossed and turned in my sleep, worrying about what the next night would bring; my eating habits might have been affected and I would have become depressed; I probably would have chosen to focus on one thing at a time, and stopped meeting Debbie.

Not now. My experiences with Mr. Crepsley and the Cirque Du Freak had changed me. I was able to handle two different roles. In fact, I liked the variation: tracking the vampire at night made me feel big and important - Darren Shan, protector of the sleeping city! - and seeing Debbie in the afternoons let me feel like a normal human boy. I had the best of both worlds.

That stopped when Mr. Crepsley zoomed in on the next victim - the fat man.