The eagerly anticipated HBO true crime doc Beware the Slenderman is finally premiering this month, focusing on the case of two 12-year-old girls who stabbed their friend in the woods on behalf of “Slender Man,” a fictional internet legend.
Morgan Geyser and Anissa Weier were both charged as adults in the attempted homicide case. Their parents were shocked—not simply because of the atrocity of the crime, but because a monster invented in a 2009 Photoshop challenge on the Something Awful forums was allegedly the motive.
“It was a picture of this Slenderman character and Jack Skellington,” said Anissa’s father Bill Weier in the documentary, reported People. “At the time, it didn’t seem to be anything inherently dangerous.”
Beware The Slenderman director Irene Taylor Brodsky interviews the girls’ parents in the documentary, as well as other people close to the case. But unlike other recent true crime docs, it doesn’t seek to prove that Geyser and Weier are wrongfully accused, or that there is some deeper corruption involved in the case.
“In no way is this a whodunit. It’s a whydunit. It’s a howdunit. How could this have happened? And the answers are very complex,” Brodsky told People.
Beware the Slenderman premieres at 10 pm on Jan. 23. Geyser and Weier, meanwhile, go to trial this summer. They have pled not guilty.