The Pebble Code

The first time I noticed it was three days after I returned from Naoko’s place in the highlands of Sumatra. I was in my flat on the fifth floor of a tower block in Bristol, and I heard five sharp knocks against the living room window. It was 3:47 PM, a time when no one would be throwing pebbles—and from that height, a pebble would have to be shot from a slingshot to reach. I laughed it off, thinking it was a bird. But the pattern repeated at 3:47 every day for a week. Five knocks, a second apart, as if someone was tapping the glass from the outside.

At night, the flat began to make noises. Not the usual creaks of a building settling, but sounds like tiny pebbles being dropped on the floorboards, or the ceiling. At first, it was sporadic. Then it became a rhythm—always five taps, always in groups of five. I started recording them on my phone to prove I wasn’t going mad. Each recording captured the taps clearly, as if someone were right next to the microphone, yet the audio showed no one there.

One night, I woke at 12:45 to the sound of my neighbours laughing from the flat next door. I remembered thinking that at 12:45 on a Tuesday, they usually kept quiet. Then I heard a deep jolt, like an earthquake. My bed shook violently, and I instinctively jumped out and stood in the doorway. But the shaking stopped as abruptly as it began, and the laughter had ceased. I stood there, gripping the doorframe, listening to my own heartbeat. That’s when I heard it: five soft knocks on the interior of my bedroom door, as if someone was on the other side, giving a friendly greeting.

For a week, I slept with the lights on. I could not shake the feeling that something had attached itself to me in Sumatra. Naoko’s house was an old colonial bungalow surrounded by tea plantations. The locals avoided it after dark, claiming it was ‘hantu pebble’—a spirit that counts pebbles. Naoko laughed it off, but I remember one night she told me never to knock back. ‘If you hear five knocks, don’t answer with another five. It will think you’re playing the game.’

I tried to forget that warning. But the knocks grew more insistent. They started happening during the day, not just at night. I would be in the bathroom, brushing my teeth, and hear five raps on the window pane. I’d spin around, but there was nothing. My flat began to smell of damp earth and rotting leaves. I found small piles of grey pebbles in the corners of my rooms, as if someone had sprinkled them there while I wasn’t looking.

One evening, I saw a shadow pass under my door—a long, thin shadow, like a finger sliding across the floor. I screamed, but when I opened the door, the hallway was empty. The knocking continued, now not just in my flat but inside my head. I could hear it in my own heartbeat: five beats, pause, five beats.

Desperate, I called Naoko. She answered groggily, and I could hear the humidity of Sumatra in her room. ‘You have to come back,’ she said. ‘You need to do the ritual. Break the pattern.’ She told me to take five pebbles, each the size of my thumb, and throw them out the window of my bedroom at 3:47 AM precisely. But I had to do it without looking out. ‘It’s the only way to break the contract,’ she insisted.

That night, I gathered five small grey pebbles from a flower pot on my balcony. At 3:47, I opened the window and threw them out, one by one, with a second between each. I kept my eyes shut, but I heard them land on the ground far below, five distinct taps though they should have been silent. When I opened the window, the glass was gone. Instead, there was a hole in the wall, leading to a dark corridor that smelled of tea leaves and old wood. In the distance, I saw a figure—a small woman with long black hair, facing away. Without thinking, I knocked five times on the wall to get her attention. She turned around, and her face was the face of Naoko, but older, with grey skin and eyes like dry riverbeds. She smiled, and I saw her mouth was full of pebbles, moving like a maraca.

I slammed the window shut, but there was no window. I was already in her corridor, standing on the pebbles that crunched under my feet. She opened her mouth, and a thousand stones poured out, filling the corridor, rising around my ankles. I tried to run, but the pebbles climbed higher, covering my legs, my waist, my chest. The last thing I heard was the soft patter of five stones dropping onto the floor, just like the first time I returned from Sumatra.

Now I am the one who knocks. I wait outside windows of high-rise flats, tapping five times, a second apart, hoping someone will answer. If you hear me, don’t knock back. But if you do, and you feel the floor shake, remember: you were never safe. You just didn’t know it yet.