It is a prequal of a book by Niel Gaimen called The Graveyard Book and is based on the back story of the serial killer called The Man Jack. It is a fanfiction.
A story told from the perspective of a ghost, forced to relive old memories of how she died. She recounts her sad story from the very beginning of her real life "horror" story, how she met her killer, and how he ended her life.