In small-town Virginia, police are called to a gruesome crime scene where a family has been massacred in their own house. In the basement, an even more disturbing discovery is made: the partially buried corpse of a nude woman.
The cops take this unidentified victim to a small, family-run morgue, where they ask proprietor Tommy Tilden to perform an urgent forensic analysis in order to help determine what happened at the blood-stained house.
Tommy's son Austen cancels a date with his girlfriend in order to help his father perform an autopsy, and the two Tildens set about their grisly examination in the morgue basement.
Working late into the night as they methodically peel back layers of skin, muscle, and bone, Tommy and Austen are baffled by the lack of external signs of trauma on the victim and the alarming extent of her internal injuries.
Increasingly perplexed and frustrated by these forensic anomalies, the pair begins to succumb to late-night jitters, getting spooked at apparitions that seem to be lurking in the shadows. As the dread mounts and the atmosphere gets thick with evil, it becomes apparent that the Tildens' fate is intertwined with a darkness that neither of them can comprehend.