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.

Research scientist Landis Barker self-experiments to quantify the haunting of a Lambda Technologies branch in Port Moore after a particle accelerator test goes wrong and the entire building goes into lockdown.

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.

As Val organizes a civil defense force to protect the town, her daughter Abigail goes missing; Jimmy leads the charge to find the girl, employing Roman's medium skills and anyone who's willing to set foot in the forest on the outskirts of town.

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.

With his body in critical condition, Jimmy's spirit becomes trapped in the nightmarish ghost realm; Roman pursues Dan, looking for answers about his mother's death.

An arrival from Lambda headquarters gives the town hope for the first time in weeks as they distribute supplies and promise to get everyone off the island; the eccentric young CEO Daphne Vikander takes great interest in Roman.

Lambda's attempts to experiment on their confiscated pod go awry when a grotesque Norm emerges from the ghost vessel and unleashes havoc on anything in his path; a monster hunt begins.

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.