I finally made it to the landing and, with one final indelicate grunt, pulled the trunk onto it after me. It slid easily now, and after a few more shoves I had it teetering precariously on the edge; one last nudge would be enough to send it over. But I wanted to see it shatter—my reward for all this work—so I got up and carefully shuffled toward the edge until I could glimpse the floor of the gloomy chamber below. Then, holding my breath, I gave the trunk a little tap with my foot.

It hesitated for a moment, wobbling there on the edge of oblivion, and then pitched decisively forward and fell, tumbling end over end in beautiful balletic slow-motion. There came a tremendous echoing crash that seemed to rattle the whole house as a plume of dust shot up at me from below and I had to cover my face and retreat down the hall until it cleared. A minute later I came back and peeked again over the landing and saw not the pile of smashed wood that I had so fondly hoped for, but a jagged trunk-shaped hole in the floorboards. It had fallen straight through into the basement.

I raced downstairs and wriggled up to the edge of the buckled floor on my belly like you would a hole in thin ice. Fifteen feet below, through a haze of dust and darkness, I saw what remained of the trunk. It had shattered like a giant egg, its pieces all mixed up in a heap of debris and smashed floorboards. Scattered throughout were little pieces of paper. It looked like I’d found a box of letters, after all! But then, squinting, I could make out shapes on them—faces, bodies—and that’s when I realized they weren’t letters at all, but photographs. Dozens of them. I got excited—and then just as quickly went cold, because something dreadful occurred to me.

I have to go down there.

* * *

The basement was a meandering complex of rooms so lightless I may as well have explored them blindfolded. I descended the creaking stairs and stood at the bottom for a while, hoping my eyes would eventually adjust, but it was the kind of dark there was no adjusting to. I was also hoping I’d get used to the smell—a strange, acrid stink like the supply closet in a chemistry classroom—but no such luck. So I shuffled in, with my shirt collar pulled up over my nose and my hands held out in front of me, and hoped for the best.

I tripped and nearly fell. Something made of glass went skidding away across the floor. The smell only seemed to get worse. I began to imagine things lurking in the dark ahead of me. Forget monsters and ghosts—what if there was another hole in the floor? They’d never find my body.

Then I realized, in a minor stroke of genius, that by dialing up a menu screen on the cellphone I kept in my pocket (despite being ten miles from the nearest bar of reception), I could make a weak flashlight. I held it out, aiming the screen away from me. It barely penetrated the darkness, so I pointed it at the floor. Cracked flagstone and mouse turds. I aimed it to the side; a faint gleam reflected back.

I took a step closer and swept my phone around. Out of the darkness emerged a wall of shelves lined with glass jars. They were all shapes and sizes, mottled with dust and filled with gelatinous-looking things suspended in cloudy fluid. I thought of the kitchen and the exploded jars of fruits and vegetables I’d found there. Maybe the temperature was more stable down here, and that’s why these had survived.

But then I got closer still, and looked a little harder, and realized they weren’t fruits and vegetables at all, but organs. Brains. Hearts. Lungs. Eyes. All pickled in some kind of home-brewed formaldehyde, which explained the terrific stench. I gagged and stumbled away from them into the dark, simultaneously grossed out and baffled. What kind of place was this? Those jars were something you might expect to find in the basement of a fly-by-night medical school, not a house full of children. If not for all the wonderful things Grandpa Portman had said about this place, I might’ve wondered if Miss Peregrine had rescued the children just to harvest their organs.

When I’d recovered a little, I looked up to see another gleam ahead of me—not a reflection of my phone, but a weak glimmer of daylight. It had to be coming from the hole I’d made. I soldiered on, breathing through my pulled-up shirt and keeping away from the walls and any other ghastly surprises they might’ve harbored.

The gleam led me around a corner and into a small room with part of the ceiling caved in. Daylight streamed through the hole onto a mound of splintered floorboards and broken glass from which rose coils of silty dust, pieces of torn carpet plastered here and there like scraps of desiccated meat. Beneath the debris I could hear the scrabble of tiny feet, some rodentine dark-dweller that had survived the implosion of its world. In the midst of it all lay the demolished trunk, photographs scattered around it like confetti.

I picked my way through the wreckage, high-stepping javelins of wood and planks studded with rusting nails. Kneeling, I began to salvage what I could from the pile. I felt like a rescue worker, plucking faces from the debris, brushing away glass and wood rot. And though part of me wanted to hurry—there was no telling if or when the rest of the floor might collapse on my head—I couldn’t stop myself from studying them.

At first glance, they looked like the kind of pictures you’d find in any old family album. There were shots of people cavorting on beaches and smiling on back porches, vistas from around the island, and lots of kids, posing in singles and pairs, informal snapshots and formal portraits taken in front of backdrops, their subjects clutching dead-eyed dolls, like they’d gone to Glamour Shots in some creepy turn-of-the-century shopping mall. But what I found really creepy wasn’t the zombie dolls or the children’s weird haircuts or how they never, ever seemed to smile, but that the more I studied the pictures, the more familiar they began to seem. They shared a certain nightmarish quality with my grandfather’s old photos, especially the ones he’d kept hidden in the bottom of his cigar box, as if somehow they’d all come from the same batch.

There was, for instance, a photo of two young women posed before a not-terribly-convincing painted backdrop of the ocean. Not so strange in and of itself; the unsettling thing was how they were posed. Both had their backs to the camera. Why would you go to all the trouble and expense of having your picture taken—portraits were pricey back then—and then turn your back on the camera? I half-expected to find another photo in the debris of the same girls facing forward, revealing grinning skulls for faces.

Other pictures seemed manipulated in much the same way as some of my grandfather’s had been. One was of a lone girl in a cemetery staring into a reflecting pool—but two girls were reflected back. It reminded me of Grandpa Portman’s photo of the girl “trapped” in a bottle, only whatever darkroom technique had been used wasn’t nearly as fake-looking. Another was of a disconcertingly calm young man whose upper body appeared to be swarming with bees. That would be easy enough to fake, right? Like my grandfather’s picture of the boy lifting what was certainly a boulder made from plaster. Fake rock—fake bees.

The hairs on the back of my neck stood up as I remembered something Grandpa Portman had said about a boy he’d known here in the children’s home—a boy with bees living inside him. Some would fly out every time he opened his mouth, he had said, but they never stung unless Hugh wanted them to.

I could think of only one explanation. My grandfather’s pictures had come from the trunk that lay smashed before me. I wasn’t certain, though, until I found a picture of the freaks: two masked ruffle-collared kids who seemed to be feeding each other a coil of ribbon. I didn’t know what they were supposed to be, exactly—besides fuel for nightmares; what were they, sadomasochistic ballerinas?—but there was no doubt in my mind that Grandpa Portman had a picture of these same two boys. I’d seen it in his cigar box just a few months ago.

It couldn’t have been a coincidence, which meant that the photos my grandfather had shown me—that he’d sworn were of children he’d known in this house—had really come from this house. But could that mean, despite the doubts I’d harbored even as an eight-year-old, that the pictures were genuine? What about the fantastic stories that went along with them? That any of them could be true—literally true—seemed unthinkable. And yet, standing there in dusty half-light in that dead house that seemed so alive with ghosts, I thought, maybe …

Suddenly there came a loud crash from somewhere in the house above me, and I startled so badly that all the pictures slipped from my hands.

It’s just the house settling, I told myself—or caving in! But as I bent down to gather the photos, the crash came again, and in an instant what meager light had shone through the hole in the floor faded away, and I found myself squatting in inky darkness.

I heard footsteps, and then voices. I strained to make out what they were saying, but I couldn’t. I didn’t dare move, afraid that the slightest motion would set off a noisy avalanche of debris all around me. I knew that my fear was irrational—it was probably just those dumb rapper kids pulling another prank—but my heart was beating a hundred miles an hour, and some deep animal instinct commanded me to be silent.

My legs began to go numb. As quietly as I could, I shifted my weight from one leg to the other to get the blood flowing again. A tiny piece of something came loose from the pile and rolled away, making a sound that seemed huge in the silence. The voices went quiet. Then a floorboard creaked right over my head and a little shower of plaster dust sprinkled down. Whoever was up there, they knew exactly where I was.

I held my breath.

Then, I heard a girl’s voice say softly, “Abe? Is that you?”

I thought I’d dreamed it. I waited for the girl to speak again, but for a long moment there was only the sound of rain banking off the roof, like a thousand fingers tapping way off somewhere. Then a lantern glowed to life above me, and I craned my neck to see a half dozen kids kneeling around the craggy jaws of broken floor, peering down.

I recognized them somehow, though I didn’t know where from. They seemed like faces from a half-remembered dream. Where had I seen them before—and how did they know my grandfather’s name?

Then it clicked. Their clothes, strange even for Wales. Their pale unsmiling faces. The pictures strewn before me, staring up at me just as the children stared down. Suddenly I understood.

I’d seen them in the photographs.

The girl who’d spoken stood up to get a better look at me. In her hands she held a flickering light, which wasn’t a lantern or a candle but seemed to be a ball of raw flame, attended by nothing more than her bare skin. I’d seen her picture not five minutes earlier, and in it she looked much the same as she did now, even cradling the same strange light between her hands.

I’m Jacob, I wanted to say. I’ve been looking for you. But my jaw had come unhinged, and all I could do was stare.

The girl’s expression soured. I was wretched looking, damp from rain and dust-covered and squatting in a mound of debris. Whatever she and the other children had been expecting to find inside this hole in the floor, I was not it.

A murmur passed among them, and they stood up and quickly scattered. Their sudden movement knocked something loose in me and I found my voice again and shouted for them to wait, but they were already pounding the floorboards toward the door. I tripped through the wreckage and stumbled blindly across the stinking basement to the stairs. But by the time I made it back to the ground floor, where the daylight they’d stolen had somehow returned, they had vanished from the house.

I bolted outside and down the crumbling brick steps into the grass, screaming, “Wait! Stop!” But they were gone. I scanned the yard, the woods, breathing hard, cursing myself.

Something snapped beyond the trees. I wheeled around to look and, through a screen of branches, caught a flash of blurred movement—the hem of a white dress. It was her. I crashed into the woods, sprinting after. She took off running down the path.

I hurdled fallen logs and ducked low branches, chasing her until my lungs burned. She kept trying to lose me, cutting from the path into the trackless forest and back. Finally the woods fell away and we broke into open bogland. I saw my chance. Now she had nowhere to hide—to catch her I had only to pour on the speed—and with me in sneakers and jeans and her in a dress it would be no contest. Just as I started to catch up, though, she made a sudden turn and plunged straight into the bog. I had no choice but to follow.

Running became impossible. The ground couldn’t be trusted: It kept giving way, tripping me into knee-deep bog holes that soaked my pants and sucked at my legs. The girl, though, seemed to know just where to step, and she pulled farther and farther away, finally disappearing into the mist so that I had only her footprints to follow.

After she’d lost me, I kept expecting her prints to veer back toward the path, but they plowed ever-deeper into the bog. Then the mist closed behind me and I couldn’t see the path anymore, and I began to wonder if I’d ever find my way out. I tried calling to her—My name is Jacob Portman! I’m Abe’s grandson! I won’t hurt you!—but the fog and the mud seemed to swallow my voice.

Her footprints led to a mound of stones. It looked like a big gray igloo, but it was a cairn—one of the Neolithic tombs after which Cairnholm was named.

The cairn was a little taller than me, long and narrow with a rectangular opening in one end, like a door, and it rose from the mud on a tussock of grass. Climbing out of the mire onto the relatively solid ground that ringed it, I saw that the opening was the entrance to a tunnel that burrowed deep inside. Intricate loops and spirals had been carved on either side, ancient hieroglyphs the meaning of which had been lost to the ages. Here lies bog boy, I thought. Or, more likely, Abandon hope, all ye who enter here.

But enter I did, because that’s where the girl’s footprints led. Inside, the cairn tunnel was damp and narrow and profoundly dark, so cramped that I could only move forward in a kind of hunchbacked crab-walk. Luckily, enclosed spaces were not one of the many things that scared the hell out of me.