Lanford Police Department officers congratulate fellow police officer Will Loren for rescuing teenage hostages Anna Cole, Monica Matthews and Julie Sims from John Michael Malum, leader of a demon-worshipping cult called “The Flock” who ritually kills to women whose bodies are then fed to pigs. . Inexplicably, Will soon goes on a sudden killing spree throughout the police station before finally killing himself.
A year later, for her first assignment as a rookie cop, Will’s daughter, Jessica Loren, requests a solo shift handling overnight security at the old police station while all regular activity shuts down. diverted to a new facility. Before her turn, Jessica visits her father’s grave, where she has an awkward run-in with her estranged alcoholic mother Diane.
Members of Malum’s Flock accost Jessica on her journey to the old station. Jessica also watches the cult members riot at the new police station.
Arriving at the old station, Jessica has an awkward encounter with the abrasive officer Grip Cohen. After putting her off about her family history, Cohen leaves Jessica alone in the building.
Jessica finds a secret compartment inside her father’s old locker containing additional files and newspaper clippings on Malum’s crimes. Jessica puts away a flash drive. Images of an occult symbol that the cult leaves in pig’s blood around the city are later identified as the symbol of a demonic entity known as “The Baron of the Temple”.
Jessica finds the symbol painted on the back of a live pig mysteriously abandoned outside the station. Jessica finally gets the pig inside, but is then forced to shoot it.
A wandering murmur cryptically breaks into the station. Jessica subdues the man, but she is left locked in a holding cell with him. Before finally escaping the room, Jessica hears her father’s voice in the dark and sees a shocking vision of three people hanging from the ceiling.
Remembering that she didn’t hear him yell at anyone when he first arrived, Jessica calls Officer Cohen to question him about the apparent paranormal activity possibly haunting the station. Cohen simply insults Jessica before hanging up.
Jessica sees a prostitute named Marigold being thrown out of a car outside. As Jessica treats her injuries, Marigold tells how she was at that station a year ago when Malum and two of her followers, Dorothea and Kitty, hanged themselves in the waiting area. Jessica is confused by a conflicting official story, which claims that Malum was killed in an officer-involved shootout. Jessica throws Marigold out after the woman is suddenly charmed and begins to rant.
A series of taunting phone calls culminates in someone claiming they are holding Monica Matthews, one of the three survivors Will Loren rescued, hostage. The voice also tells Jessica that her father started something that the cult plans to finish that night. Jessica calls the other police station to make another report on the strange events and learns that Monica Matthews disappeared that night along with Ana Cole and Julie Sims.
On the flash drive, Jessica finds video footage of the Malum Flock brutalizing his victims. Another file shows Jessica, a tranced doppelganger, apparently in her room with her. Additional visions, including one of a disfigured entity chasing her out of range, continue to haunt Jessica.
Jessica calls the other station for help upon discovering that she has been chained up inside the building. The voice she answers back verifies the rumor that John Malum died at that station.
Video footage from Malum and his accomplices being interrogated apparently shows Jessica’s father behaving strangely after seeing a strange figure. Officer Price, who later arrives with his partner Hudson to transfer the drifter, confirms to Jessica that her father was acting strangely before killing his fellow officers, and Will warned everyone to avoid the holding area because Malum was somehow he was still there even though he died. .
A combination of visions and video footage reveals that Jessica’s mother Diane was once a member of Malum’s herd and that Jessica was christened by Malum as a baby. Jessica confronts her mother about the truth when Diane arrives at the station. Diane explains that Malum promised that Jessica would be a crucial part of a bigger plan, but after Diane began suffering disturbing visions, she went on the run. Malum finally found his family a year ago, prompting Will to end the cult. Diane walks away from Jessica after becoming entranced by a figure.
Jessica begins to question reality as she continues to experience visions of cultists killing hostages, cultists invading the building, and dead cops lurking in the hallways. Jessica shoots the homeless man during one of these visions. Malum is also revealed to be the phone voice Jessica had been talking to at the other police station.
Visions lead Jessica to a dark room where she finds Malum, resurrected as a ghoulish figure, sitting on a makeshift throne. Cultists and dead cops seemingly surround Jessica before separating from her to make way for a creature that has come to feed on her spirit.
Jessica suddenly returns to an empty hallway in reality, but inadvertently shoots her mother, killing her. With visions of cultists and dead cops continuing to taunt her, Jessica finally shoots herself in desperation. Two figures drag Jessica’s corpse and place her on a throne next to Malum’s. Jessica’s head suddenly twitches.
