The boy's father lost his mind in the winter of 1922. I was fourteen at the time and little Aleksy Malenhov had just turned nine. My family and I lived across the valley from the Malenhovs' crumbling cottage, and on a Sunday morning in snow-covered December my father noticed something unusual. It was the absence of chimney smoke. A trivial detail, you might think, but the villagers of Renkassk knew different. It meant that no fire kept the Malenhov cottage warm that day, and winters ninety miles north of the Arctic Circle proved fatal if not prepared for.

"Viktor's fire never goes out in winter," my father said, peering out through the window of our house. I watched as his breath cooled on the pane.

"What if he's out of firewood?" I asked at his side.

"The man's a carpenter, Stefan," he replied tautly. "He has more logs stacked up outside his home than he knows what to do with."

By noon my father decided he would cross the field of snow and aid them, afraid that Viktor had grown sick.

"I have to go now, Stefan," he told me, pulling the collar of his coat up to his jaw.

My ears pricked. "To the Malenhovs'? I want to come with you."

Papa hacked and coughed mucous into his handkerchief. "You can't. I'll call on your cousin Pyotr first, and he'll come and help me."

"Let me and Pyotr go," I protested, putting myself between him and the door. "You're ill. If you go out into the cold you'll –"

He shoved me aside like a twig. "When you're a man of this community you leave nobody suffering, and in turn they'll grant you the same. If I ever suffer, I want you to remember that." He heaved a sack of wood over his shoulder and stepped out into the snow. My shoulders sagged as I watched his grey silhouette retreat into the mist.

"Close the door," my mother said behind me. She lay on a heap of blankets in front of our woodstove, staring into the flames until it sucked the moisture from her eyes. She cried a lot in winter; some kind of seasonal depression. I eased the door back into its frame and returned to my position at the window.

Two hours later something burst through the conifers. I jumped up, realising it was Papa, and opened the door for him with a smile. He tumbled through, powdered white with snow and ruddy-cheeked, and his breath caught hoarsely in his throat. My smile faded when I saw he was in shock. I asked him what was wrong with Viktor, but it was yet another hour before Papa had calmed down enough to answer me. He sat in his armchair with blank eyes, gripping a mug of hot broth so hard he might break it.

From what I could gather, he'd approached the Malenhov cottage and seen the untouched, snowy pyramid of logs by the side of it. He told me of the sudden dread he'd felt upon seeing it, knowing for certain that something had happened to Viktor some days ago. When he followed Pyotr inside the cottage, he found Mr Malenhov face-down on the floor and unable to move. He said the carpenter's fingers had turned blue, his brown eyes were cloudy and he was completely unresponsive to his name. Pyotr had hurried to his side, being the closest thing we had to a doctor in Renkassk, while Papa sought out little Aleksy. He found the boy shivering in his bed with his coat, scarf and boots on, hungry and pale, but otherwise well.

"Did he say what happened to Viktor?" I prompted when my father fell quiet, seemingly unable to bring himself to continue. "Did he see anything, Papa?"

According to the rest of the tale, Aleksy told him Viktor had come home two days ago in the middle of the night, crawling on his hands and knees, and in tears. When Aleksy had rushed over to him, his father collapsed on the spot and not moved since. Aleksy was too frail to lift him and he didn't know what to do besides hope. The boy had covered him in a blanket and fed him as best he could, but he couldn't bear his father's staring, open-mouthed visage for long. Aleksy was frightened of him. Viktor had been as amiable a man as any, but the man that my father found that day would unnerve him and Pyotr for the rest of their lives.

The news of Viktor's eerie decline spread through the village of Renkassk far quicker than we'd have liked. Offers to adopt Aleksy Malenhov rippled through the valley, though the boy rejected them, vowing not to leave his father alone in the cottage in hopes he might return to his former self when winter subsided ... But by the time spring thinned the ice, rumour had it that Viktor had become gaunt and sickly. His blank eyes stared wide and his mouth hung open into his chest, displaying rotten teeth and a dry, yellow tongue. Saddest of all, I heard that Aleksy's mind and body had deteriorated too, and he became a weak child, dependent on his father's silent company.

Spring brought with warmer weather, and so the snow began to melt in the vast woodland between Renkassk and Darakyev. It meant school time for Aleksy Malenhov, no matter how much he objected. Renkassk had no schoolhouse to call its own, though the neighbouring town of Darakyev educated boys between the ages of five and fourteen. Six days a week, twenty-four weeks of the year I had crossed the tundra, braved the woodland and attended the schoolhouse eight miles away, but my term in education ended last year. Still, I offered to take Aleksy halfway to the town every morning at dawn, since the other boys dared not offer.

Like any other day, I perched him on my bicycle seat before taking to the pedals. It was an old bike with skinny wheels and rust on the frame, but it served its purpose well enough. Aleksy held on to me around the middle and I laboured to the top of a gentle hill so that the rest of his journey was an easy few miles down.

I hopped off the bike and kicked down the stand. "You know where you're going?" I asked as I helped him down from the seat. "You remember where you are?"

"Net."

Same answer every morning. I pointed beyond the woodlands. "Down there and through the trees is Darakyev, where the schoolhouse is, remember?"

He withdrew his hands into his sleeves and shook his head.

"Fine," I sighed. I bent down to his level and took him by the shoulders. "Listen closely to me then, Aleksy, because I'm going in minute. Follow the trail from here down to the trees and you'll find Strange One's Pass. It's a woodland road with a fingerpost, where your papa would take you to help gather firewood before he got ill. Right?" Recognition flickered in his icy blue eyes. "Follow it, stay on it, until you reach the frozen river. The schoolhouse is just beyond the bridge – you can't miss it. Got that?"

"Strange One's Pass," he repeated.

I smiled at him; my mother said that was my charm. "Da. See you in –"

Aleksy cocked his head. "Why's it called Strange One's Pass?"

"I don't know. Maybe the people in Darakyev named it that."

"Well, I don't want to go there," he mumbled. "I think that's where we saw the Folveshch."

I stood. He told me the same thing every morning. "No you didn't, Aleksy. Nobody's seen the Folveshch because it's just some stupid folklore somebody told about you when you were little. My grandpapa told me it, but when you're older you'll realise it's not true."

"It is true. Papa and I saw it. We –"

"Stop talking about it."

"But it's the truth. It happened."

"Nobody knows what happened to your father," I said, grabbing my bike handles in a huff, "but whatever it was, you can't keep blaming it on the supernatural. It was God. How many times do I have to tell you?"

I watched him for a moment as he lifted the leather strap of his satchel over his head and snapped it across his chest in silence. He looked so much smaller in his long coat and too-big boots. I nodded towards the town in the distance and said, "Get a move on, or you'll be late for school."

He tied his scarf around his mouth and ears, and waved goodbye.

Little Aleksy would reach the school in an hour, and eight hours later I'd cycle to the top of the hill again and lift him onto the seat for the ride back to Renkassk. It was the same routine, same instruction, same conversation on loop every day. But as my papa said, one day we'd be men of the community, and nobody, not even the weakest of us, should be left forgotten. I let out the horrible cough I'd been hiding all the way up here, and took to the pedals again.

After seeing Aleksy off, my next stop would be his home. Viktor Malenhov had once been the village carpenter and never short of work. His home was not shabby in the way you'd envision neglect, but a working-man's home would always be the last of his projects and Viktor was no exception. He'd been a quiet man with hardened palms, with sleeves rolled up past his elbows even in the harsh winters, and nobody alive had seen him without a beard. He'd had two wives, but I wasn't sure which, if either, was Aleksy's mother.

I reached the cottage half an hour later, though depending which way the wind blew it could take longer sometimes. The warmer months exposed the jagged path to their cottage, but still the degree of incline made it a difficult trip on two wheels. A long time ago I would look forward to visiting the Malenhovs with Papa, but the sight of their cottage nowadays made my blood run cold, knowing who was inside.

Viktor, after only four months since my father and Pyotr had found him, had deteriorated into something just shy of a skeleton. I pushed aside the wooden door and it creaked on its hinges, sending something cold slithering down my spine. Viktor sat in his armchair by their low-burning fire, with his mouth agape, and his blank eyes staring straight through me.

"Hello," I said, in case he could still understand me. An awful rasping sounded in his throat and the dark hairs on my arms prickled. I supposed it was the only form of communication he could make now that his body was stuck like wax. The village never worked out what his condition was, or why he'd lost the ability to move or speak. He'd been healthy and active, sound of mind and sociable, yet there he sat across from me in his armchair, a man reduced to a life of sightless silence.

I tried to pretend he wasn't there during my daily visits, whistling tunelessly as I'd throw more logs into the woodstove and check their supplies. I'd bring a loaf of Mama's bread so that Aleksy could tear it up in the broth I'd set to stew – "put in some ducks," he'd say. Some days I'd even leave a knob of salted butter or a jar of preserve for him. On rare occasions I'd set down some old clothes or toys that my mother came across, or even go over his homework and correct it. That day I put a children's book on his bed for him to read. As for Viktor, the most I did for him was kept him warm.

People said it was a shame what happened to the Malenhovs, and I agree; it was terrifying. But kind Viktor's fate was no more than the start of it, and by the time winter came around again in 1923, more glum news passed from lip to ear. Polio survivor Iakov Yakunin had been found face down somewhere on the tundra, hypothermic, blind and petrified. I didn't dare visit him at his home, but Pyotr told me the cripple had the same condition as Mr Malenhov. And, worse, only six months after he'd proposed to the love of his life. My cousin told me of Iakov's hanging jaw, his wide cloudy eyes, and his sudden inability to move or communicate ... Just like Viktor. What did it mean?

"What kind of a life is that for good men?" Papa said, as he brushed the snow from his boots after our day's work on the building site in Darakyev. He coughed horribly; his bubbling anger only made it sound worse. "They'd be better off dead, the pair of them. I know I would, if it was me. Why did God bring this on them? Why now?"

"I don't know, Papa," I replied, and hung my coat up on the back of the door.

"You hear what Iakov's little brother claims?"

"Georgiy? No, why?"

"He said he and Iakov saw the Folveshch this November. How ridiculous."

At that, I caught his eye. "Are you being serious?"

"Well, he seemed serious, but then he's only eleven. He said they saw the Foul Thing as though it was as ordinary as seeing a fox. You know, I've not heard of the Folveshch since your grandpapa used to scare you with it like he did to me." He hunched over in imitation of his father and said in his raspy voice, "Close all the curtains at night, syna, or the Foul Thing peers in."

"Funny you should mention all that old crap," I told him as I plopped down into Grandpapa's old rocking chair, "because Aleksy Malenhov says Viktor saw it too. He says they saw it on Strange One's Pass."

"That's where the little Yakunin boy says he saw it, too." He coughed and spluttered again into his hand. "Ha! Stefan, why are we talking about this? I don't entertain such folklore anymore, and yet here we are talking about it as though there's something to see. Those two boys attend the same school. Children talk. Nothing more. More than likely that weird Aleksy kid has been telling tales."

But the winter after that, it was Papa who collapsed, screaming his throat sore about the Folveshch.