"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.