Beware The Slenderman argues that modern boogeymen aren’t terrifying—their effects are

A documentary about two 12-year-old girls stabbing one of their close friends nearly to death shouldn’t feel the need to work to unsettle its audience. The raw story behind Beware The Slenderman, HBO’s rich and disturbing documentary, goes overlong attempting to convey the menace of the modern folkloric monster. From its opening scene of a video version of someone encountering the eerie being, the film returns time and again to the wide swath of internet-based stories, illustrations, and video clips offering up portrayals of this iconic (and extremely new—the myth was invented in 2009) character, in hopes of communicating just how frightening and influential it could be in the minds of a couple of young and impressionable kids. Which is understandable, but it doesn’t need to carry over the menace into the awful real-world crime this mythology spawned. When you’ve got clinical descriptions of a girl repeatedly stabbing another girl, ladling on blasts of synth is overkill.

But if it’s sometimes overbearing, Beware The Slenderman is also often riveting, the kind of “how could this happen?” story that rewards lengthy exploration. Even at nearly two hours, it never grows tedious or bogged down in minutiae. The basic contours of the narrative are simple, and possibly still familiar to those who recall hearing of the tragic and mystifying crime back in May 2014. The media’s account was essentially accurate: Three young friends in suburban Wisconsin woke up the morning after a sleepover, went out into the woods, and two of the them stabbed the third girl as an offering to Slenderman. A fictional monster birthed from the Something Awful forum, Slenderman started as a contest dedicated to trying to create realistic and believable modern monsters, via a combination of clever imagery, videos, and old-fashioned storytelling, after which it blossomed on the Creepypasta Wiki. The victim survived, but in the months that follow, the documentary cameras trail the shattered parents of the two would-be murderers as they try to make sense of their children’s shocking crime.

(A quick tutorial: The Slenderman is an unnaturally tall, black-suit-wearing gentleman with lengthy, spindly arms and a featureless face. He usually lives outside, traumatizing, stalking, and sometimes abducting or killing people, often children. As he targets you, the closer he gets, the more victims begin to experience debilitating physical effects. However, there’s also sometimes an element of appeal included in stories, in which bullied or hurt children will find protection from him, and he’ll spirit them away to live with him. There’s a wide variety of different interpretations, and the explosion of Slenderman fan art and online folklore testifies to the malleability of the myth.)

The most immediate takeaway from interviews with the families of Morgan Geyser and Anissa Weier are how supportive and engaged they seemed to be. Morgan’s mother and Anissa’s father both come across as smart, sensitive, and involved parents who were completely blindsided and shattered by what their kids did. Still, it’s clear early on that Morgan has emotional issues. From her blithe manner in the police interrogation videos threaded throughout, the lack of empathy her mother mentions as being a point of concern early in life becomes apparent. (At one point, she casually asks if Bella—her best friend since fourth grade, whom either Morgan or Anissa stabbed 19 times—is dead, and shrugs at the cop’s “I don’t know” response. “I was just wondering,” she muses.) Anissa’s father and her favorite teacher spend more time talking about her loneliness. She was an outcast at school, and would regularly have crying jags about her lack of friends. Absent the context of the now-infamous folklore of Slenderman, this would still be a harrowing investigation into the identities of two troubled kids who committed a seemingly inexplicable assault.

But the Slenderman mythos lends an engaging if somewhat off-putting element of media power and the psychological influence of technological to the proceedings. Richard Dawkins shows up to explain the concept of memes, and by his qualifications, Slenderman is a potent meme indeed. The film smartly traces the history of fables such as the brothers Grimm’s Pied Piper Of Hamlin, showing how societal fears take shape in our bedtime stories and nursery rhymes. Slenderman is merely one of the most successful and adaptable recent versions of the tales, one that echoes the pied piper’s appeal as well as his menace. To ignored or bullied kids, Slenderman can take on an aura of protectiveness, a supernatural bulwark against the cruelty of the world. The movie wisely avoids sliding from correlation to causation, avoiding the trap of “heavy metal is responsible for Columbine”-type foolishness. Instead, it manages to instill a sense of justification in both the kids’ fear and admiration of Slenderman, even as we, like their disbelieving parents, wonder how they could possibly take the stories as true.

Stylistically, the film pivots between intimate first-hand accounts and gliding, distant shots of the neighborhood in which the crime took place. Director Irene Taylor Brodsky films the woods and buildings of Waukesha, Wisconsin in bright, ebullient colors, trying to contrast the warm appeal of the natural real world with the faded, digital darkness of the Slenderman videos. The voices of Morgan and Anissa, their parents, and the representatives of the legal system tasked with bringing their case to court are interlaced between the two worlds Brodsky depicts, showing how impressionable minds could end up blurring the fictional world with the real one. Many of the shots of the Geyser and Weier family stand at a distance, the camera peeking through windows and beyond door frames, emphasizing the isolation and feelings of vulnerability that follow from their ordeal. (The family of the victim appears to have declined to participate in the film.)

However, a late-in-the-film reveal throws a new light over the entire situation, one that both goes a long way toward explaining things but also illuminating the danger of pat answers to thorny tragedies that belie such solutions. It’s clear why Brodsky held it back; it would have offered an Occam’s razor of rationalization to something the director feels shouldn’t be explicable. Whatever personal traumas or emotional damage these girls possess, their crime still creates an uneasy link between the creative world of modern folklore and the dangers of our current “post-truth” culture, in which anything might be true merely by dint of not being able to prove it isn’t true. Plenty of peaceful adults believe in ghosts, aliens, and chemtrails, regardless of logic; is it so crazy to think the rapidly changing world of technologically meme-ified society would play a pivotal role in convincing some kids desperate for a better world that violence might bring it about?

For thoughts on, and a place to discuss, plot details we can’t reveal in this review, the Beware The Slenderman’s Spoiler Space will go live after the broadcast at 10 p.m. Eastern.