HBO just released a trailer for Beware the Slenderman, a new documentary set to debut on January 17. Spoiler alert: it’s terrifying.The film narrates the events surrounding the highly publicized stabbing of a 12-year-old girl in Wisconsin by two of her classmates. The suspects, Morgan Geyser and Anissa Weier , also 12, claim that they only stabbed their friend to appease a fictional entity they believed to be real: Slenderman.Slenderman is a figure created in a meme, of all things. He blossomed online via fan fiction that depicted him stalking, abducting, and being generally horrible to children. He is between 6 and 14 feet tall with white skin, no face, a black suit, and tentacle-like appendages. Creepy. Geyser and Weier believed this e-bogeyman would hurt their families unless they killed their friend.Thankfully, the victim survived, but Geyser and Weier's attempted murder made national news and prompted a media panic about the effect of the internet on kids. Beware the Slenderman not only follows the girls' trial and the mythology of this tall dude, it brings up complicated questions about how accountable young people should be when their imaginations literally run wild.The trailer honestly makes those killer clowns from last month look friendly. After the week we’ve just had, another violent white man in a suit is the last thing we need right now. I’m already having nightmares.