The plot is centered around a woman named Sarah who regains consciousness in an abandoned hospital with no memory of how she got there. A mysterious voice tells her to find the secrets of the hospital. With a cell phone, which is her map, she must explore the haunted hospital and its criminal past in order to escape.
As Sarah explores the hospital and the adjacent prison, she begins to learn of the hospital’s past, where twelve witches were executed and buried on the hospital grounds, with a thirteenth witch escaping death due to her turning in the other twelve witches. After gathering all of the clues, Sarah realizes that she is the descendant of the thirteenth witch, which is why the spirits of the other twelve witches are haunting her.