Just as troubled medium Roman Mercer prepares to leave the small town of Port Moore, an earthquake strikes the Alaskan island and awakens a supernatural force bent on destruction.

As churchgoers flourish in numbers, Reverend Dan soothes the anxieties of the townspeople. When the hauntings escalate to a possession of a young boy, Dan wrestles with the thought of performing an unsanctioned exorcism.

The town leans on skeptical and steadfast handyman Doug after Port Moore's social structure begins to collapse, but when Doug's dead daughter persuades Roman to deliver a message, Doug's well being rapidly deteriorates.

A power outage sends Port Moore into a tailspin and somehow makes the ghosts stronger, prompting Roman, Jimmy, Landis and Doug to trek up to the dam to get the power back, but a long-buried town secret threatens to tear the group apart.

Landis and Jimmy try to make sense of the museum artifact; Karla is with ghost-child and it's growing fast; Abigail's physical condition deteriorates, prompting Marilyn to finally realize that whatever is inside her daughter isn't normal.

While Daphne gathers the power she needs to launch her accelerator test, civil unrest breaks out in town when Paolo refuses to open the bar, and a mob pursues Roman, Landis, Jimmy and the McGrath-Dufresnes.

While the ghosts build a resistance against Roman, Port Moore survivors draw straws in preparation for their final battle, a quest to connect the two halves of the artifact in the ghost realm.