There are the everyday fears of the Internet age—identity theft, online radicals, your mom following you on Instagram—and then there are more ineffable ones. Who knows what horrors lurk in the corners of the Internet that you don’t visit in your daily browsing? That question provides the inspiration for a genre of online fiction known as “creepypasta,” which can be thought of as the digital version of the kinds of scary stories usually told around campfires. Creepypasta (explaining the etymology of that word would, like much on the Web, confuse more than it would enlighten) pops up on message boards or on Reddit, usually without any author attribution. Like a campfire story, it usually claims to describe real events, in the mode of “I was surfing the Internet the other day, and look what I found.” One of the first examples I came across, and one of the most famous, describes a visit to a fictional Web site called normalpornfornormalpeople.com. The powerfully distressing videos the author describes finding there include an encounter between a woman and an ape, the memory of which still sometimes keeps me up at night.

Recently, I’ve been losing sleep over another example of the form, maybe the most potent Internet scary story I’ve yet come across: a Web series called “Petscop.” It began in March, when a YouTube user uploaded a video featuring what appeared to be a nineteen-nineties-era PlayStation game called Petscop. The description said only, “The game I found.” The clip was formatted as a “let’s play,” a popular genre of YouTube video in which gamers play video games while narrating over them. True to let’s-play form, this Petscop video was narrated by an adenoidal young man. “So, this is just to prove to you that I’m not lying about this game that I found,” the man, whose name is purportedly Paul, says. “I’m just going to walk you through everything that I’ve seen so far.”

If the first job of creepypasta is to establish an air of authenticity, “Petscop” is on solid ground. When I was growing up, my local Blockbuster was full of this kind of low-quality game, coughed up by small production companies hoping to appeal to undiscerning kids like me. Paul explores a brightly colored polygonal world, collecting trinkets and capturing poorly animated creatures called “pets.” At first glance, all that sets this game apart from dozens I played in the nineties is that the avatar Paul controls isn’t a tomb-raiding archaeologist or a bandicoot but an unfriendly-looking biped with an enormous green, Darth Vader-esque head.

But then, after catching a handful of pets, Paul let’s the other shoe drop. “The reason we’re here,” he says, “is because in the note that came with this, which is short, the first line, in all capital letters, I’m gonna read it, it says: ‘I WALKED DOWNSTAIRS AND WHEN I GOT TO THE BOTTOM, INSTEAD OF PROCEEDING, I TURNED THE RIGHT AND BECAME A SHADOW MONSTER MAN.’ ” The same note, whose text is reprinted in the corner of the screen—and whose origins, like the origins of the game, are never explained—includes instructions to input a special code, which Paul does. And then things get weird.

Paul is suddenly in a shadowy expanse of what might be grass. He’s surrounded by darkness. “There’s nothing out here, as far as I’ve seen,” he says. “But, actually, I think there is something out here. I just haven’t seen it yet.” In the following videos in the series, Paul explores the game’s aggressively strange, disconcerting underworld. From the grassy expanse, he descends into a sort of cave or dungeon, where he finds, among other things, a little boy’s grave. In a cellar under a shed, Paul finds a crying child. Later, he discovers a cello-shaped red apparatus, referred to simply as “tool,” that allows him to input questions. By and by, the apparatus turns pink and its answers turn sinister.

Who are you?

TURN OFF PLAYSTATION.

Why?

MARVIN PICKS UP TOOL HURTS ME WHEN PLAYSTATION ON.

It’s a chaotic, disturbing, and, at first, incoherent series of images. But games like Petscop—the simplistic puzzle platformers of my youth—have a familiar structure: you start at point A, you solve puzzles, defeat bosses, and, ultimately, inevitably, you arrive at point B. As Paul continues to play, it seems clear that Petscop abides by that structure. A code on the grave allows Paul to access a series of bedrooms, which eventually leads him to a room set up for a birthday party, where he collects a green key. Paul, it seems, is on his way toward point B; he’s driven to play by the same need to understand that drives us to watch.

By the time I discovered Petscop, its fandom resembled something like an ad-hoc detective agency. A Petscop-specific subreddit was formed, a wiki established. Research revealed that no game called Petscop was ever actually released, nor did the company that ostensibly made it exist. It was, then, a work of internet horror fiction masquerading as reality. In other words: creepypasta, albeit on an order of magnitude more complicated than most. What most intrigued me, given how elaborate the series is, was the mystery of its authorship. Somewhere out there, someone was making these videos, and whoever it was had cloaked himself and his intentions in the darkness of digital anonymity. More than anything else about “Petscop,” it’s this evocation of the mystery of the online world and its inhabitants that makes it, for me, the king of creepypasta.

The video “Petscop 10,” posted on May 31st, gave no indication that it might be the last in the series. When two weeks passed without a new upload, a sense of anxiety began to grip the fandom. After a month, when no new Petscop videos had materialized, a sense of confusion and despair took hold. Fans assumed that they must have been missing something. Was that sign near the start of the game a reference to a poem by Michael Rosen about an abusive teacher? Was Paul digitally altering his voice to make himself sound younger? Like apocalyptic cultists, the sleuths divined dates of importance, dates when more Petscop might arrive. They commiserated when those dates came and went. Tensions arose, as they often do among frustrated obsessives, along with an antagonism toward new members and ideas. “Stop turning this sub into a cesspool of toxicity,” one Redditor wrote. The antagonism, though, was driven by a sense of optimism. Go to the Petscop subreddit, which I do once a week or so, and what you’ll find are people who are certain that the path to point B is out there, if only they are smart enough to find it.