“No,” Gretchen pulls out her phone and starts dialing. “There is supposed to be a one-beastie-per-night rule in place.”

That’s a relief. Or it would be if it were still true.

“What about during the day?” I want to ask as many questions as possible while she’s answering. Who knows how long this opportunity will last.

“They don’t come out when the sun is up.” She dials the phone and holds it to her ear. “They’re nocturnal, I guess.”

With Gretchen’s attention fully on her phone call, I turn mine to the room around me. I instantly forget the crazy news that just moments ago threatened to overwhelm me, the news that I have a sister and a heritage and, apparently, a destiny. Instead, I am hypnotized by row after row of books.

I’m not really such a bookworm—my academic specialty veers more toward the digital—but I appreciate the amount of data and research contained in these volumes. It lures me out of the chair and toward the shelves.

My fingers trail respectfully over their spines as I scan the titles. There’s an entire case of books on martial arts and fighting techniques. Another two full of books on mythology and ancient Greece. The rest are titles on a variety of minor subjects, like computers and technology and geology and cartography. What those have to do with monster fighting I’m not sure, but they must be useful.

I’m a little gaga over all the books, but it’s the final case that captures my attention. Its shelves are full of white three-ring binders. Not so unusual, I suppose, but the spine labels promise something very unusual inside: MINOTAURS. HYDRAS. SERPENT HYBRIDS. CHIMERAS. LAELAPSES. UNIDENTIFIED SPECIES.

With a quick glance at Gretchen, who has left her chair and is staring out over the Bay, I pull the one labeled MINOTAURS off the shelf and flip through. There are sections on history and myths, traits and characteristics, preferences, sociology, physiology, and battle tactics. There are myths and legends about the minotaurs. A table of reported sightings. A detailed anatomical drawing, with a big red circle around the back of the neck.

“Come on, Ursula!”

Gretchen’s boots squeak on the sparkly white tile as she starts pacing back and forth, dialing and redialing her phone. With no luck, judging from the curse that punctuates the end of each attempt. With a final curse, she throws the phone onto the table in the middle of the room.

I slide the minotaur binder back into place. After a quick estimate, I conservatively calculate that there must be over two hundred binders. Two hundred different kinds of monsters, with valuable hunting information trapped inside the pages. The whole collection should really be digitized. Maybe even made into a smartphone app so Gretchen can get the info she needs anywhere, anytime. That could be a lifesaver sometime.

“Where is Ursula?” Gretchen snaps. “It’s not like her to disappear for days at a time without letting me know.”

She sounds really worried, and she doesn’t seem like the worrying sort.

“How long has she been gone?” I ask.

Gretchen spears me with a look, and I’m pretty sure she forgot I was here. Or maybe thinks I’m to blame for the weirdness going around and her missing mentor. I hope it’s the first, because I spotted what I thought was a knife handle sticking out of her boot when she carried me out of the club. I confirmed it when her pant leg was rolled up earlier. I bet she knows how to use it too.

Finally, reluctantly, she says, “A few days. Maybe a week.”

“Does she leave often?”

“Yes,” Gretchen answers. “But she usually sends me an email or a text so I know she’s okay.”

“She could be somewhere with no signal,” I suggest.

“Yeah, maybe,” Gretchen agrees.

I think she’s humoring me.

For what feels like an hour Gretchen stares blankly at the table and I stare blankly at Gretchen. Like I’m staring in the mirror. I mean, it’s a little freaky. Our faces are identical. And even without an adoption record or a DNA test, I know without a doubt she’s my sister. My twin. I can feel it in the same way I feel Thane when he sneaks up behind me. I just know.

“So . . . ,” I finally say to break the silence. “What do we do now?”

“How should I know?” Gretchen barks.

I jump back a little at her harsh tone.

“Everything’s going sideways at the moment. Ursula’s missing, monsters are breaking the rules”—she spears me with a glance—“you show up in the middle of it all.”

Even though I didn’t do anything but move to a new town, I feel a little guilty. Gretchen obviously thinks these changes might have something to do with me, and how do I know that they don’t?

“I’m sorry, okay?” she says before I can apologize, still sounding agitated but a little more calm.

I give her a little slack. “No problem,” I say. “You’re worried about your mentor. I understand.”

It’s a lot to take in all at once. Multiple monsters, missing mentor, long-lost twin. No wonder she’s a little snappish.

She runs a hand over her hair, swiping her bangs back across her braid.

“Look, I think the best thing you can do,” she says, her tone final and far more mature than our sixteen years should have made her, “is to go back to your world. Forget about this one. Go back to your life. You’ll be safer there.”

What? “I—”

“I’ll drive you home.”