On Saturday, two 12-year-old girls in Waukesha, Wisconsin, identified as Morgan Geyser and Anissa Weier,  were arrested on charges  of attempted first-degree murder for luring a fellow classmate into the woods, where they allegedly held her down and stabbed her 19 times. According to court documents, the girls could have been encouraged to do this by the online fictional character, Slenderman. The criminal complaint says the two girls were trying to become something called a “proxy of Slender” by murdering someone.

A bicyclist found the stabbed girl on the side of the road, alive, and called for help. She was in stable condition on Monday in the hospital.  The complaint says the victim was stabbed near her heart, and she was “one millimeter away from certain death.” Slenderman is a fictional character and Internet meme that often appears in horror stories, videos and images. One of the suspects told police that Slenderman is the site’s supposed leader, and to climb into his realm, a user must kill someone.

Geyser and Weier are being charged as adults and appeared in court Monday. Bail was set for each in the amount of $500,000, Waukesha County District Attorney Brad Schimel said.