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.

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.

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.

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.