“Slenderman: Online Obsession, Mental Illness, and the Violent Crime of Two Midwestern Girls,” by Kathleen Hale (Grove Press)
The seemingly senseless stabbing of a young girl by two of her school friends in the Waukesha, Wisconsin, woods in 2014 made international headlines when it became known that the two perpetrators were under the sway of Slenderman, a fictional Internet demon that they had become convinced was real.
