"You don't understand." Lila tosses back her long blond hair. "He's not a tick, Mary. Sebastian loves me too much to bite me. But I know I can change his mind. Because he wants to be with me forever, as much as I want to be with him forever. I know it. And after tomorrow night, we will be together forever."

"What's tomorrow night?" Adam wants to know.

"The prom," I say woodenly.

"Right," Lila prattles on. "Sebastian's taking me. And though he doesn't know it yet, he's going to give in to me there. Just one bite and I'll have eternal life. Come on, you guys, how cool is that? Wouldn't you want to live forever? I mean, if you could?"

"Not that way," I say. Something inside of me aches. Aches for Lila, and aches for all the girls who've gone before her. And will come after her, too, if I don't do something about it.

"He's meeting you at the dance?" I force myself to ask her. It's hard to speak, because all I want to do is cry.

"Right," Lila says. Her face still has the same vacant expression she wore inside the club, as well as earlier today in the lunchroom. "He'll never be able to resist me-not in my new Roberto Cavalli gown, with my neck all exposed beneath the silver light of the full moon..."

"I think I'm going to throw up," Ted volunteers.

"No, you're not," I say. "You're going to take Lila home. Here." I reach into my satchel and pull out a crucifix and two containers of holy water, then hand them to him. "If Drake shows up-although I don't think he will-throw these at him. Then get yourself home, after you've dropped off Lila."

Ted looks down at what I've shoved into his hands. "Wait. That's it?" he wants to know. "We're just going to let him kill her?"

"Not kill," Lila corrects him cheerfully. "Turn me. Into one of his kind."

"We aren't going to do anything," I say. "You guys are going to go home and leave this to me. I've got it under control. Just make sure Lila gets back safely. She should be all right until the dance. Evil spirits cannot enter an inhabited house unless invited!" I narrow my eyes at Lila. "You didn't invite him inside, did you?"

"Whatever," Lila says, tossing her head. "Like my dad wouldn't go too ballistic if he found a guy in my room."

"See? Go home. You, too," I add, to Adam.

Ted takes Lila by the arm and begins to lead her away.

But Adam, to my surprise, stays where he is, his hands buried deep in his pockets.

"Um," I say to him. "Is there something I can do for you?"

"Yes," Adam says calmly. "You can start at the beginning. I want to know everything. Because if what you're telling me is true, if it weren't for me, you'd be a speck on the wall in the club back there. So start talking."

Adam

If you had told me just an hour or two ago that I'd be ending my evening with a trip to Mary-from-U.S.-History-class's penthouse apartment over in the East Seventies... well, I'd have told you that you were high.

But that's exactly where I find myself, following Mary past her sleepy doorman (who doesn't raise so much as an eyebrow at her crossbow), and then up the elevator to her place, which is decorated in mid-nineteenth-century Victorian chic-at least as near as I can judge, considering all the furniture looks like it came out of one of those boring miniseries my mom likes to watch on PBS, featuring girls named Violet or Hortense or whatever.

There are books everywhere-and not Dan Brown paperbacks, either, but big, heavy books, with titles like Demonology in Seventh-century Greece and A Guide to Necromancy. I look around, but I don't see a plasma screen or an LCD. Not even a regular TV.

"Are your parents professors or something?" I ask Mary as she throws down the crossbow and heads to the kitchen, where she pulls open the fridge and reaches for two Cokes, one of which she hands to me.

"Something like that," Mary says. This is what she's been like the whole way to her place: not exactly brimming with the explanations.

Not that it matters, though, since I already told her I'm not leaving until I get the whole story. The thing is, I really don't know what to think about all this so far. On the one hand, I'm relieved Drake isn't who I thought he was-Mary's ex-boyfriend. On the other hand... a vampire?.

"Come on," Mary says, and I follow her because... well, what else am I supposed to do? I don't know what I'm doing here. I don't believe in vampires. I think Lila's just gotten herself involved with one of those freaky goth dudes I saw on Law & Order that one time.

Although Mary's question-"Then how do you explain his disappearance from the dance floor into thin air like that?"  -  bugs me. How did the guy do that?

Then again, there are tons of questions like that one that I don't have the answers for. Like this new one that occurred to me: How can I get Mary to look at me the way Lila looked at that guy, Drake?

Life is full of mysteries, as my dad likes to say, many of which are also wrapped up in enigmas.

Mary leads me down a dark hallway toward a partly open door, from which light spills. She taps on the door, then says, "Dad? Can we come in?"

A gruff voice says, "By all means."

And I follow Mary into the strangest room I've ever seen. At least in a penthouse apartment on the Upper East Side.

It's a laboratory. There are test tubes and beakers and vials everywhere. Standing in front of some of them is a tall, white-haired-professor type in a bathrobe, messing around with a concoction in a clear container that's bright green and vigorously generating large amounts of smoke. The old dude looks up from this and smiles as Mary comes into the room, his green-eyed gaze-a lot like Mary's-darting toward me curiously.

"Well, hello," the guy says. "I see you've brought a friend home. I'm so glad. I've been thinking lately that you spend far too much time alone, young lady."

"Dad, this is Adam," Mary says casually. "He sits behind me in U.S. History. We're going to my room to do homework."

"How nice," Mary's father says. It doesn't seem to occur to him that the last thing a guy my age is likely to be doing in a girl's bedroom at two in the morning is homework. "Don't study too hard, now, children."

"We won't," Mary says. "Come on, Adam."

"Good night, sir," I say to Mary's dad, who beams at me before turning back to his smoking beaker.

"Okay," I say to Mary as she leads me down the hall once more, this time to her room... which is surprisingly utilitarian for a girl's bedroom, containing only a large bed, a dresser, and a desk. Unlike in Veronica's room, everything is put away, except for a laptop and an MP3 player. I take a quick look at Mary's play list when she's busy rifling around in the closet for something. Mostly rock, some R&B, and a little rap. No emo, though. Thank God. "What's going on? What's your dad doing with all that stuff?"

"Looking for a cure," Mary says from the closet, her voice muffled.

I've moved across the ornate Persian carpet toward her bed. There's a framed photo on her nightstand. It's of a pretty woman, squinting into the sunlight and smiling. Mary's mother. I don't know how I know it. I just do.

"A cure for what?" I ask, picking up the photo for a closer look. Yep, there they are. Mary's lips. Which, I haven't been able to stop noticing, are kind of curled up at the ends. Even when she's mad.

"Vampirism," Mary says. She emerges from the closet holding a long red dress. It's wrapped in clear plastic from the dry cleaner's.

"Uh," I say, "I hate to be the one to tell you this, Mary. But there's no such thing as vampires. Or vampirism. Or whatever it is."

"Oh yeah?" The ends of Mary's mouth are curled up even more than usual.

"Vampires were just made up by that guy." She's laughing at me. I don't mind, though, because it's Mary. It's better than her ignoring me, which is what she's done for most of the time I've known her. "That guy who wrote Dracula. Right?"

"Bram Stoker did not make up vampires," Mary says, the smile vanishing. "He didn't even make up Dracula. Who's an actual historical figure, by the way."

"Yeah, but a dude who drinks blood and can turn into a bat? Come on."

"Vampires exist, Adam," Mary says quietly. I like how she says my name. I like it so much that I don't even notice at first that she's staring at the photo I'm holding. "And so do their victims."

I follow the direction of her gaze. And nearly drop the photo.

"Mary," I say. Because it's all I can think of to say. "Your... your mom? Is she... did she..."

"She's still alive," Mary says, turning to throw the red dress, in its slippery clear plastic bag, onto the bed. "If you can call it living," she adds, almost to herself.

"Mary..." I say in a different tone of voice. I can't believe it.

And yet I do. There's something in her face that makes it clear she's not lying. Also something that makes me long to wrap her in my arms. Which Veronica would say is sexist. But there you go.

I let go of the lip I've started chewing. "Is that why your dad-"

"He wasn't always like that," she says, not looking at me. "He used to be different, when Mom was here. He... he thinks he can find a chemical cure for it." She sinks onto the bed beside the dress. "He doesn't want to believe that there's only one way to get her back. And that's killing the vampire who made her into one."

"Drake," I say, sinking down onto the bed beside her. It all makes sense now. I guess.

"No," Mary says with a quick shake of her head. "His father. Who happened to stick with the original family name of Dracula. His son just thinks Drake sounds a little less pretentious and more modern."

"So... why were you trying to kill Dracula's kid, if his dad is the one who..." I can't even bring myself to say it. Fortunately, I don't have to.

Mary's shoulders are hunched. "If killing his only kid doesn't get Dracula to come out of hiding so I can kill him, too, I don't know what will."

"Won't that be, uh... kind of dangerous?" I ask. I can't believe I'm sitting here talking about this. But I can't believe I'm in Mary-from-U.S.-History's bedroom, either. "I mean, isn't Dracula, like, the head of the whole operation?"

"Yes," Mary says, looking down at the photo I've laid between us. "And when he's gone, Mom will finally be free."

And Mary's dad won't have to worry about finding a cure for vampirism anymore, I think, but don't say out loud.

"Why didn't Drake just, uh, turn Lila tonight?" I ask. Because this has been bothering me. Among other things. "I mean, back at the club?"

"Because he likes to play with his food," Mary says emotionlessly. "Just like his dad."