Riley Flynn returns to his hometown of Crockett Island, a tiny offshore fishing village reeling economically due to an oil spill that crippled its fishing industry, after serving four years in prison for a drunk driving crash that killed a young woman. Having lost his faith during his incarceration, Riley struggles to reintegrate with the town's devout Catholic community, including his parents, Annie and Ed, teenage brother Warren, childhood sweetheart and expectant mother Erin Greene, and zealous parishioner Bev Keane. The community is also joined by Father Paul Hill, a young priest claiming to be a temporary replacement for the aging Monsignor Pruitt, who is on pilgrimage to the Holy Land. While out at night with his friends Ooker and Ali, Warren spots strange movement in a remote island area populated by feral cats, later mauled by an unseen entity. The following night, Riley sees the figure of Monsignor Pruitt walking along the beach amidst a raging storm, but the figure soon vanishes. The next morning, hundreds of dead cats are discovered along the beach.