The Amityville Asylum (2013)

In 1974, a cloaked figure gives Ronald DeFeo Jr. a shotgun, which DeFeo uses to kill all six of his relatives at 112 Ocean Avenue in Amityville, New York. Decades later, the house is torn down and replaced by the High Hopes Psychiatric Hospital, which has just hired a new custodian named Lisa Templeton. Lisa is given a tour of the hospital by the maintenance man, Delaney, and told that she will be responsible for cleaning Ward X, a wing which houses criminally insane murderers like the sexual sadist Jerry Kimble, cannibalistic vigilante Dennis Palmer, occultist Sadie Krenwinkel, and a "Patient X" who is implied to be DeFeo. On her first night working at the hospital, Lisa encounters the ghost of Allison DeFeo, she is reprimanded for reporting this to the incredulous head of security, Hardcastle, and is sexually harassed by an orderly named Pemberton.

Palmer escapes from his cell one night and kills Pemberton before cannibalizing Kimble. He is subsequently tortured with electroshock equipment by Pemberton's fellow orderlies, and when Lisa witnesses this, she is browbeaten into silence by Hardcastle. Lisa researches the history of Amityville and discovers that, back in the 18th century, the Satchem, a Native American cult, settled in the area after being run out of Salem, Massachusetts by Christians. The Satchem believed that making annual sacrifices of six people would result in them being gifted with immortality by a God called the Dark Master. The Satchem were eventually wiped out by a witch hunter named John Underhill and buried in a mass grave on the site of what would later become 112 Ocean Avenue. Krenwinkel is a member of a modern-day cult that has adopted the beliefs of the Satchem.

Lisa learns that Doctor Elliot Mixter, the owner of High Hopes, testified at Krenwinkel's trial; when she brings Mixter evidence that Krenwinkel has somehow acquired occult paraphernalia and access to the internet, he is revealed to be in league with Krenwinkel, and has Lisa unlawfully committed to Ward X. Lisa is broken out of her cell by Delaney while Mixter arms Patient X with a shotgun and sends him on a rampage through High Hopes. Patient X murders Krenwinkel, Palmer, and Hardcastle before going after Lisa and Delaney, who encounter possessed patients (one of whom rips his own face off) and Allison's ghost while trying to flee High Hopes. After Patient X kills Delaney, he is killed by Lisa. Lisa confronts Mixter, who taunts her into attacking him, which results in Lisa being gunned down by the NYPD. The massacre at High Hopes is blamed on Lisa.

A year later, Mixter gives a television interview, during which he cheekily implies that he is now immortal while promoting his book, High Hopes, Broken Dreams.