The story of “Slenderman” is rooted in Internet lore and involves a faceless, often tall man who lurks about and urges people to do ghastly things.

This mythical beast would have probably gone the way of other web phenomenon which had appeared on sites like Something Awful and Creepypasta had it not been for the exploits of two 12-year-old girls, Morgan Geyser and Anissa Weier, who lured their classmate, then-11-year-old Payton Leutner, out into the woods in in Waukesha, Wisconsin and stabbed her 19 times as a means of proving Slender Man’s existence.

“Many people do not believe Slenderman is real,” one of the girls said, according to the criminal complaint. “[We] wanted to prove the skeptics wrong.”

Beware the Slenderman debuted earlier this year at South by Southwest and chronicles Geyser and Weier’s obsession, and the events that led them out into that wooded area on that fateful day.

Director Irene Taylor Brodsky told BuzzFeed, “The narrative does not revolve around guilt or innocence, but instead the court’s deliberation whether the girls should be tried as adults or children.”

The film will debut on HBO on January 23, 2017.

Words by Alec Banks
Features Editor

Alec Banks is a Los Angeles-based long-form writer with over a decade of experience covering fashion, music, sports, and culture.