In the fall of 1976, a small psychology lab in Pennsylvania became the unwitting home to the only government-confirmed case of possession. The U.S. military assumed control of the lab under orders of national security and, soon after, implemented measures aimed at weaponizing the entity. The details of the inexplicable events that occurred are being made public after remaining classified for nearly forty years.

The script centers on a young woman with a long-term phobia of the bogeyman, who voluntarily checks herself into a mental health facility with the hope of conquering her overwhelming fears. However, much to her horror, she discovers that some things are terrifying on purpose, and confronting her demons was not the best course of action.