Serial killer H.H. Holmes builds a hotel in Chicago complete with gas chambers, trap doors, acid vats and other sinister constructions.
The Pennhurst State School and Hospital, once an institution for physically and mentally disabled individuals, is allegedly haunted by the spirits of its neglected patients and abusive employees.
The restless spirits of dismembered murder victims offer clues about the Mad Butcher of Kingsbury Run, a serial killer who stalked the shantytowns of 1930s Cleveland.
Four locations connected to the 1692 Salem witch trials are plagued by the restless spirits of the innocent.