Kyle, two other agents, and I went down three rickety wooden steps.

It was quiet and dark. An agent worked a flashlight around.

Then we saw the killer. He saw us too.

A well-built teenage boy in a soiled black leather studded vest and black jeans was crouched in the far corner of the cellar, waiting for us. He had a crowbar. He leaped up and began swinging it over his head. He was growling. It had to be Irwin Snyder, the boy who had killed his parents. He was so damn young, just seventeen. What had gotten into his head?

Gold fangs protruded from his mouth. Contacts made his eyes appear bloodred. His nose and eyebrows were pierced with at least a dozen tiny gold and silver hoops. He was tightly muscled and over six feet tall. He'd been a star football player before he suddenly dropped out of school.

Snyder continued to growl at us. He stood in an oozing groundwater puddle and didn't seem aware of it. His eyes were glazed and seemed to be set way back in his skull.

"Back off!" he shouted. "Y'all have no idea how much shit you're in. Y'all have no goddamn idea! Get the fuck out of here! Get out of our house!"

He was still swinging the heavy, rusted crowbar. We stopped moving. I wanted to hear whatever he had to say.

"What kind of shit are we in?" I asked Snyder.

"I know who you are," he shouted, spraying spit all the way across the room. He was in a murderous rage. He looked stoned beyond comprehension.

"Who am I?" I asked him. How could he know?

"You're fucking Cross, that's who," he said, and bared fang-capped teeth, the smile of a madman. His answer shook me up. "The rest of y'all are FBI dogs! Y'all deserve to die! You will! The Cross don't work here, assholes."

"Why did you kill your mother and father?" Kyle asked from his place on the stairs.

"To free 'em," Snyder sneered. "Now they're free as little birdies in the air."

"I don't believe you," I said. "That's bullshit."

He continued to growl like a barnyard dog. "Smarter than you look, Cross."

"Why did you use metal fangs when you bit them? What does the tiger mean, Irwin?" I asked another couple of questions.

"You already know or you wouldn't ask," he said, and laughed wickedly. His real teeth were yellow and nicotine stained. His black jeans were filthy and looked as if they'd been dipped in ashes. The leather vest had studs missing. The cellar smelled awful, like spoiled meat. What had happened down here? I almost didn't want to know.

"Why did you kill your parents?" I asked again.

"Killed them to free myself," he screamed. "Killed their asses 'cause I follow the Tiger."

"Who's the Tiger? What does the Tiger mean?"

His eyes danced with mischief. "Oh, you'll see soon enough. You'll see. Then you'll wish you didn't."

He dropped the crowbar and reached into his jeans, and I rushed him. Irwin Snyder had a stiletto knife in his right hand. He swiped the knife at me, and I pivoted away.

I wasn't fast enough, and the blade sliced my arm. It burned like hell. Snyder screeched in triumph. He lunged at me again. Fast, athletic, forward.

I managed to wrestle the knife from his hand, but he bit into my right shoulder. He went for my neck! Kyle and the others were all over him now.

"God damn it!" I yelled in pain. I punched his face. He bit me again. This time on the back of my hand. Damn, it hurt!

The FBI agents had trouble pinning him down as he hurled a stream of curses and threats at all of us. They were afraid of being bitten.

"Now you're one of us!" he screeched at me. "You're one of us! Now you can meet the Tiger," he howled, and laughed.

My head was aching, but I spent the next four hours questioning Irwin Snyder in a bare, white-washed, claustrophobic room at a jail in Charlotte. For the first hour or so, Kyle and I interrogated him together, but it didn't work out. I asked Kyle to leave the room. Snyder was shackled, so I felt safe being alone with him. I wondered how he felt.

My arm and hand were beginning to throb, but this was more important than my wounds. Irwin Snyder had known I was coming to Charlotte. How had he known? What else did he know? How was a vicious young killer in Charlotte connected to the rest of this mess?

Snyder was pale and unhealthy looking, with a scruffy goatee and sideburns. He stared at me with eyes that were dark, very active, intelligent enough.

Then he laid his head down on the Formica tabletop, and I lifted him right out of his chair by his hair. He cursed at me for a full minute. Then he demanded to see his lawyer.

"Hurts, doesn't it?" I said. "Don't make me do it again. Keep your head offthe table. This isn't nap time. It isn't a game either."

He gave me the finger, then put his head back down on the table. I knew he'd been getting away with this type of shit at school and in his home for years. But not here, and not with me.

I yanked him by his greasy black hair again, even harder this time. "You don't seem to understand the King's English. You murdered your parents in cold blood. You're a killer."

"Lawyer!" he screamed. "Lawyer! Lawyer! I'm bein' tortured in here! I'm bein' beaten by a cop! Lawyer! Lawyer! I want my fuckin' lawyer!"

With my free hand I grabbed his chin. He spit on my hand. I ignored it.

"Listen to me now," I said. "Listen! Everybody else from the house is at the station in the city. You're the only one out here with me. No one can hear you. And you're not being beaten. But you are going to talk to me."

I yanked his hair again — as hard as I could without actually pulling out a clump. Snyder shrieked, but I knew I hadn't hurt him much.

"You killed your mother and your father with a claw hammer. You bit me twice. And you stink to high heaven. I don't like you, but we're going to have this talk anyway."

"Better see somebody about those bites, pig," he snarled. "You been warned."

He was still talking tough, but he cringed and pulled back when I reached for his hair again.

"How did you know I was coming to Charlotte? How did you know my name? Talk to me."

"Ask the Tiger, when you two meet. It'll happen sooner than you think."

It became clear that Irwin Snyder couldn't have committed the earlier murders. He had been out of North Carolina only once or twice in his life. Most of his contact with the outside world was over the Internet. And of course he was too young to have been involved in murders going back eleven years.

The seventeen-year-old had killed his mother and father, though. He seemed to have no remorse. The Tiger had told him to do it. That was all I had been able to get out of him. He refused to say how he had come into contact with the person or group who had such control over him.

While I was questioning Snyder, and then the others from the house, my shoulder and hand began to itch and then ache. The bites were puncture wounds, but there had been little bleeding. The bite to my shoulder was the deepest, even through my jacket, and had left prominent teeth marks, which I'd had photographed at the station.

I didn't bother going to the local emergency room in Charlotte. I was too busy. The wounds soon became extremely painful. By late morning, I had trouble making a fist. I doubted I could pull the trigger of my gun. Now you're one of us, Irwin Snyder had told me.

I wondered what group, or cell, or cult Snyder was part of. Where was the Tiger? Was it only one person? I attended a meeting with the FBI and the Charlotte police that lasted until eight that evening. The net result was that we were still nowhere near a solution. The FBI was scouring the Internet searching for messages relating to the Tiger, or any kind of tiger.