As the exorcism reaches a critical juncture, Tomas engages the demon in a desperate battle to save Andy's soul. Meanwhile, Marcus and Rose attempt to get the foster children off the island, but the demon has other plans. As the storm of the century descends upon the island, salvation may come from an unlikely source.
A visit to the foster home carries deadly consequences, as Marcus and Father Tomas attempt to draw the demon out of hiding. Rose finds herself the target of the demon's wrath. And no one suspects that a new danger may be lurking in the woods, waiting for its moment to strike. Meanwhile, Father Bennett and Mouse take the fight directly to the conspiracy as they attempt to hunt down an old adversary.
Six months after leaving Chicago, Father Tomas and Marcus Keane's travels lead them to a troubled young woman in rural Montana. On a secluded private island off the coast of Seattle, Andy Kim runs a group home for at-risk foster children, whose lives are disrupted when the state sends a social worker.