A Tragic Story of Online Obsession and Mental Illness


The 2014 Slenderman stabbings in Wisconsin, USA, shocked the local community and the world. The violence of Morgan Geyser and Anissa Weiser, the two twelve-year-old girls who attempted to stab their classmate to death, was extreme, but what seemed even more frightening was that they had done so under the influence of an internet meme, the so-called 'Slenderman'.

Slenderman tells the full story for the very first time. Morgan and Anissa's friendship could so easily not have taken the turn it did - but Morgan was suffering with early onset schizophrenia. She believed she had been seeing Slenderman for years, and that the only way to stop him killing her family was to bring him a sacrifice. Her victim miraculously survived the attack but was left deeply traumatised, while the severity of their crime meant Morgan and Anissa would be tried as adults.

is both a page-turning true crime classic and a compelling search for justice.


  • Kathleen Hale's Slenderman is a haunting, powerful, accomplished and necessary book that is impossible to put down
    Sonia Faleiro, author of The Good Girls

About the author

Kathleen Hale

Kathleen Hale is the author of two young adult novels and an essay collection. She has written for the Guardian, Hazlitt and Vice. A graduate of Harvard, she is also a writer and producer for Outer Banks on Netflix.
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