I’m wearing jeans and a Batman T-shirt in the photo, which was snapped in front of Baneberry Hall, the house lurking in the background like an eavesdropper. Its presence means I was five at the time. Because there’s no scar on my cheek, I also assume it was taken in the first three days of our stay. There’s not even a bandage.

It’s also missing in the next photo, which shows me standing with two other girls, one roughly my age and the other much older. We’re in my bedroom, lined up in front of the armoire, our eyes glowing red from the flash and giving us the look of demon children.

The younger girl I recognize. I saw the same features in the face of the woman I met last night. The only difference is a present-day hardness not evident in this younger version of herself.

Hannah Ditmer.

Which means the older girl in the photo is Petra.

She’s so pretty it takes my breath away. Long limbs, creamy skin, blond hair that’s been piled atop her head. Unlike Hannah and me, who stand stiff-backed with our arms at our sides, Petra strikes a playful pose. Hand on her hip. One leg bent in a backward kick. Flash of bare feet, toenails painted red.

We’re dressed for sleep, Hannah and me in pajamas, Petra in a large white T-shirt and Umbro shorts. She also wears a necklace—a tiny crucifix hanging from a slender gold chain.

I remember that night. Or at least the Book’s version of it. The sleepover gone terribly wrong. It was one of the first things nine-year-old me obsessed about—how I had absolutely no memory of that horrifying night. I spent nights awake, scared that what I’d read was true. Because it was indeed scary. A kind of nightmare-in-a-horror-movie scenario that no one would want to experience. But I had and couldn’t recall any of it, which meant that something must have been terribly wrong with me.

After several sleepless nights staring at the ceilings in both of my bedrooms in both of my parents’ separate homes, I began to realize that the reason I couldn’t remember the events in the Book was because they never happened.

I had assumed that included the sleepover.

But according to this Polaroid, I was wrong. There was, at some point in our twenty days at Baneberry Hall, a time when Hannah and Petra had spent the night.

At least part of it.

Petra’s in the next photo as well, standing in the kitchen with my mother. The two of them stare up at a giant hole in the ceiling in a pose of unintended synchronicity. Both in profile, their heads tilted back and their throats exposed, they could pass for mother and daughter. It makes me wonder if my mother ever saw this photograph and, if so, how it felt to see herself pictured with a younger woman of a similar nature. A girly girl. The kind of daughter she’d never have.

There are two other people in the photo, overlapping in the background. In front is an older man in flannel and jeans making his way up a ladder. Behind him is someone younger, barely visible. All I can make out is a crescent of face, a bent elbow, half of a black T-shirt, and a sliver of denim.

Walt Hibbets and my father. Two days after the kitchen incident.

Like the sleepover, it’s one of the most famous passages in the Book. And, if this photo is to be believed, also similarly rooted in truth.

I hold both Polaroids side by side, studying them, my stomach slowly filling with a queasiness that began the moment I found the shoebox. It’s the sinking feeling that comes with bad news, dashed hopes, sudden heartbreak.

It’s the feeling of realizing what you thought was a lie might be true.

Part of me knows that’s completely ridiculous. The Book is fiction, despite having the words A True Story slapped on its cover, right below the title. My mother said as much. Yet a tiny voice in the back of my head whispers that maybe, just maybe, I could be wrong. It’s the same voice that last night, right before Elsa Ditmer made her presence known, suggested the person inside the Indigo Room could have been Mister Shadow.

I hear it now, hissing in my ear.

You know it’s true. You’ve always known.

What makes it so unnerving is that I recognize that insistent whisper.

It’s my father. Sounding just like he did right before he died.

I hear it again when I fish the last two photos out of the box. The first is a shot of my father performing a prototypical selfie. Arm extended. Chin lowered. Swatch of bare wall in the background over his left shoulder. He stares straight at the camera, which makes it seem as if he’s looking beyond it, into the future, his eyes locking on mine through a distance of twenty-five years.

Never go back there, his voice says. It’s not safe there. Not for you.

Hoping my father’s whisper will go away if I’m not longer looking at his face, I flip to the last Polaroid. It was taken at a vertiginous angle from one of the windows that overlook the backyard. On the ground are two people entering the woods.

One of them is my mother.

The other is me at age five.

It’s exactly like the photo my father described in the Book. The one he took when he found the Polaroid camera. My gaze drifts against my will, moving to the left of the frame, simultaneously knowing and fearing what I’ll find there.

Sure enough, hugging the edge of the frame is a dark shape hiding among the trees.

It could be a tree trunk, darkened by shadow.

It could also be a person.

I can’t quite tell because the picture quality is so poor. It’s grainy and slightly out of focus, giving everything a jittery blur. Despite that, the dark form bears a distinct human shape.