“Okay, great,” I say. “Remember to stay out of sight. She might remember you.”

“So?” he asks. “There’s no law against grocery shopping.”

“I guess you’re right,” I say. “Sorry.” Deep breath. “All right, I’m going in.”

I walk up the steps to the office that just has to hold all the answers. I’m not sure what makes me try the silver key first—I guess I just like silver better than gold—but it works. I’m half expecting an alarm to wail or someone to jump out at me when I open the door, but almost more terrifyingly, nothing happens.

I step inside and breathe in through my nose. The place has that metallic antiseptic smell to it like a dentist’s office. There’s a vacant reception desk and a doorway leading to a hallway; I walk through and turn left: the direction that Mom came from that day I saw her here. There’s an office at the end of the hall.

When I go in, I gasp.

Three walls are covered in corkboard and pinned with photos and notes. It looks like what you’d expect in the office of someone tracking a Mafia family. Except that the photos on the walls aren’t of criminals: They’re of me, Ella, and Betsey.

I take a step closer to the wall I quickly see is mine. There are tons of notes scrawled on yellow legal paper, but one in particular catches my eye: Tendency toward fight (vs. flight)—Sympathetic Nervous System difference when compared to #1 and #2.

I step over to Ella’s wall; the phone rings and I jump.

“You scared the hell out of me!” I say.

“Sorry,” Sean says, laughing a little. “Just making sure you’re okay. Are you in?”

“I’m in.”

“And?” I feel like he’s holding his breath.

“It’s… I don’t know,” I say. “It’s an office with walls of photos of me, Betsey, and Ella, with a ton of notes. It’s like she’s monitoring us, only she lives with us. And most of it is really stupid stuff.” I take a step closer to the photos of Ella. “Like, okay, here’s an example: There’s a note pinned here about how much sleep Ella gets. Apparently she averages eight point two hours per night.”

“What the…?”

“I don’t know,” I say, moving along the wall. I notice that there are pictures of the palms of our baby hands, and fingerprints with little circles on them to show the patterns. I look from Ella’s to mine; they look the same to my untrained eye. “It’s like we’re her… project.”

“You said she was a scientist,” Sean says. “Do you think she’s like studying you or someth—”

“Oh my god!” I say loudly. I’m back in front of my wall, and in the corner, there’s a hazy black-and-white picture of Sean and me leaving his house.

“What?” he asks, concerned. “Is everything okay?”

“She knows about us,” I say flatly. “She probably knows everything.” I let the thought sink in, and after a few seconds, I start to feel okay with it. She knows and she’s let it go on. She must have a reason: Maybe it’s that deep down, she does want me to be happy.

“I don’t know about you, but I think that’s a good thing,” Sean says.

“I think it is,” I say quietly, smiling. “Hey, let me call you back. I need two hands to snoop.”

Sean laughs. “Okay, I’ll keep an eye on the mark and call you if anything changes.”

“You’ve been playing too many detective video games,” I say, laughing, too. Then, “Thanks, Sean.”

“You know it.”

We hang up and I linger on my wall for a while longer, then start going through papers on my mom’s desk. There are three stacks of more photos and notes—maybe things she hasn’t gotten around to hanging up yet—and halfway through the second one, I see a photo of a woman I recognize: the one from the gas station.

Nosy Mary.

It’s a professional photo like you’d use on a business card, printed in black and white from the Internet on regular multipurpose paper. There’s a phone number but no name written in the white margin; it’s unclear whether the number and the photo are related.

I consider calling the number until suddenly I remember thinking I saw Nosy Mary’s car when I got coffee with Alison. It dawns on me that maybe Mary’s a private investigator or something, paid by Mom to follow her own children.

My ringtone startles me; I drop the photo and answer the phone.

“Hi,” I say.

“Your mom left the store,” Sean says urgently. “She was in line to pay and she got a call and then just rushed out of the store. She abandoned her cart. At first, I didn’t follow…. I thought she’d left her wallet in the car or something, but then I saw her driving away. I ran out and followed her…. She’s going in the direction of your house.”

“How close?” I say, stepping toward the office door.

“Too close,” Sean says. “You’ll never make it back in time. I’m sorry I didn’t call sooner, but I was gunning it, trying to catch up with her.”

I’m quiet for a few seconds, considering. Then I sigh. “Well, if I’m caught out of the house anyway, I might as well get all the ammo I can. I’m going to need it.” Pause. “I’ll call you right back; I’m going to call Ella and Bet to warn them.”

From my recent calls, I redial the other spy phone, but no one picks up. I weigh the downside of having this number show up on the bill for the landline and decide that by the time the bill comes, this will all be over. I call, but no one answers there, either. I call Sean back.

“What do you want me to do now?” he asks.

“Just make sure she goes home,” I say. “Then I guess you’re off duty.”

“No problem.”

Sean and I stay on the phone while he drives, me telling him about the pictures and notes on the walls and him commenting on my mother’s utter strangeness, until he reports that Mom is turning off the main road to our house.

“Just go by,” I say, my heart sinking, thinking of Ella and Betsey having to try to tap dance out of this situation all alone. It bugs me that they haven’t called back yet.

“Stay on the phone with me, okay?” I say. Having Sean in my ear now is like a down comforter in the dark: It’s security. Sean agrees, then launches into a story about the woman who’d been in line behind Mom at the grocery store—apparently she had a total meltdown about the abandoned cart. I open my mouth to say something when suddenly, without an ounce of warning, the most electrically charged surge of panic runs through me.

I suck in my breath and put my hand to my chest as my heart rate skyrockets, seemingly without cause.

“Lizzie, what’s wrong?” Sean asks. “Are you okay?”

“I… can’t… breathe…” I say through gasps.

“What?” he asks. “Are you serious? What happened? Did you touch something weird that maybe… Are you allergic to something?”

“No,” I say, gasping. “Nothing.”

“Can you sit down?” he asks. “Put your head between your knees?” He waits a beat and then says, “I’m coming there. I’m coming to get you. Screw your mom; you need to go to the hospital.”