Bingo.

Noah is busted, and he’s actually stumbling backward, trying to find a way out of the proverbial corner.

“Great. My brother got Alexei to spy on me. Grandpa and Ms. Chancellor have you. I am covered!”

“Grace, don’t —” Noah reaches for my arm, but I push him away.

“How did you find me?” I ask.

“We followed you,” Rosie says, matter-of-fact.

“No.” I shake my head. “Not good enough. I’ve been wandering these tunnels for hours. I wasn’t even sure where I was, so how did you find me?”

I look from Noah to Rosie and then, finally, I let my gaze settle on Megan.

“We might have put a tracker on you,” she says.

“You might have what?”

Megan holds up a tiny device. “GPS location receiver. I put a transmitter in your sweater.” She eyes the ratty cardigan that I’ve been taking with me everywhere these days. “You really should clean that sometime, you know.”

“Why?” I ask.

“Well, for starters, there’s a stain on the sleeve that’s been there since —”

I cut Megan off. “Why were you following me?”

“Oh. That,” Megan says. For a moment, the three of them are silent.

“Well, see …” Noah starts slowly. “Last night, Megan called me.”

“And Noah called me,” Rosie interjects.

“We were sort of …” Noah is struggling for words.

“You’re freaking us out,” Megan says bluntly.

“You’re worried about me?” I ask.

“Well, yeah,” Noah says, as if it should be the most obvious thing in the world.

“I don’t need your worry,” I snap. “And I don’t want your pity.”

I’m pushing through them, starting back toward the door and the tunnels and the answers I’m no closer to finding.

“Maybe not,” Megan yells. “But you need our help.”

I freeze. And then slowly — very slowly — I turn. “Well, maybe I don’t want it.”

There’s something that comes from being the girl who is always left behind. I could only watch Jamie and Alexei disappear without me so many times before I got really good at convincing myself that I was better off alone.

But I wasn’t left alone, I realize now.

I was left with Megan.

“He’s going to do it again,” Megan says. “That’s what you said last night, isn’t it? That the man who killed your mother is going to kill somebody else?”

“That’s none of your business,” I say, then glare at Noah so hard that he actually pulls Rosie in front of him, a human shield.

“You think you’re the only one who’s ever lost someone?” Megan snaps. There is ice in her voice. “Do you think you’re the only one who has ever wanted to make somebody pay?”

I’ve never heard her talk like this, seen her look like this. She is nothing like Lila now. And she’s nothing like the little girl who used to bring over her Barbies, either. It’s like everything else has been camouflage. This is the Megan she has spent her whole life hiding. And for the first time in all the years I’ve known her, I realize that I have never heard Megan talk about her dad.

“Besides,” she says flatly, “you do need us.”

“I don’t need you,” I say.

“Says the girl who has wasted an entire day wandering around in circles down here,” she says.

“I know these tunnels better than anyone.” Rosie sounds almost hurt. “Maybe if you’d asked me, I could have saved you a day.”

“I have the resources of two embassies behind me,” Noah says. “You really think you’re better off without me?”

I roll my eyes, look at Megan. “I’m a genius,” she says. Everyone turns to her. “Well, I am. No use trying to soft-pedal it. Plus, my mom’s a spy. Any of you pick up covert-operations training in summer camp? Yeah. I didn’t think so.”

She has a point and, genius that she is, I’m sure she already knows it.

“So are you going to tell us now?” Rosie asks. She’s looking up at me with those huge blue eyes. It’s like she’s asking me to tuck her into bed, tell her a story. “Grace, what happened last night?”

I’m looking at the three of them. They really are here. And they really aren’t going anywhere.

I could think of a dozen reasons to send them away — a hundred. It isn’t safe. It isn’t their fight. Their parents could lose their jobs if someone were to catch us. The reasons are bubbling up on my tongue. But I can’t bring myself to say them.

Instead I blurt, “I followed the Scarred Man.”

I wait for someone to object, but no one says a thing.

“You know when he disappeared the other day?” I ask Rosie. “Well, I figured out that he must have come down here. Into the tunnels.”

“Of course!” Rosie sounds so mad at herself. “I’ve only ever come in through the public entrances where they give tours and stuff. I never knew there were hidden entrances. I should have guessed. I’m sorry, Grace.”

“Don’t be,” I tell her. “So … yesterday. I was following him again when he came down here. We walked for a long time and then he went up into some building.”

“What building?” Megan asks.

“I don’t know. That’s what I’ve been doing all day — trying to retrace our steps. But I can’t find it.”

“Why do you need to find it?” Noah asks. “What did you see?”

“I followed him inside. He was meeting someone. I couldn’t tell who, but they were talking about killing someone. He said — and I quote — ‘There are many perfectly adequate ways to die.’ And he just has to find one.”

For a moment there is nothing in the basement but the echo of the Scarred Man’s words and the drip, drip, drip of the water into the pool. It’s like sand through an hourglass, a steady, constant reminder that I’m running out of time.

“And you don’t know what building you were in?” Megan asks.

“No,” I snap in frustration.

“What did it look like?” she asks.

“Like a building! Carpet. Doors. Lights.”