‘Beware the Slenderman’: Creepy True-Crime

Like so many internet memes, the Slenderman phenomenon is known by millions of people, while millions of others have no idea what it is. I’m one of the latter, and so Beware the Slenderman, a documentary premiering Monday on HBO, was my introduction to an appalling crime that was committed at the instigation of a fictional creation.

In 2014, two 12 year-old girls in Waukesha, Wisconsin, plotted to stab a third 12-year-old. The victim, Payton “Bella” Leutner, was stabbed by a knife wielded by Morgan Geyser, after Anissa Weier urged Morgan to “go crazy.” Morgan and Anissa had fallen under the spell of an internet creation, the Slenderman, a tall ghostly figure who supposedly preys upon young girls and compels them to do bad things under the threat of death. (Bella survived the attack.)

Related: ‘Beware the Slenderman’: What You Need to Know About the Meme-Motivated Crime

The documentary does a good job of filling you in on the Slenderman mythos and how it has spread. (By the time Morgan and Anissa were arrested and awaiting trial, they themselves had become past of the nauseating Slenderman fan-fiction.) Director Irene Taylor Brodsky had access to the families of Morgan and Anissa, as well as to footage of police interrogation of the two, who freely admitted their crime.

While Morgan’s parents and some medical experts make a reasonable argument that she may suffer from schizophrenia, it’s difficult to watch Beware the Slenderman and not come to the conclusion that all of this might have been prevented if the girls’ parents — and indeed, if parents all over the country — limited their kids’ access to, and monitored their use of, their laptops, iPads, and other devices. As scary as Slenderman himself is the footage of Anissa’s parents allowing their young son, well after Anissa’s crime was committed, to continue to sit, slack-jawed, in front of an iPad playing some stupid game, responding only with grunts when the parents ask him to turn it off and get out of the house.

“I just did what the internet has told me,” is Anissa’s chilling justification for what she and Morgan did to Bella. You’re left feeling there are probably an awful lot of kids who “do what the internet” tells them to do, in ways that are both harmless and harmful.

Beware the Slenderman airs Monday at 10 p.m. on HBO.