Frank Bannister, a former architect turned ghostbuster, has developed the ability to see and communicate with ghosts after a tragic accident that killed his wife. Frank has since then left his previous profession and now makes a living by exorcising ghosts from people’s houses. However, his business is a scam; he is in cahoots with a group of friendly spirits who haunt houses so that he can then "exorcise" them for a fee. While the townsfolk see him as a charlatan, Frank's unique abilities are genuine, but he uses them for dubious ends. His life takes a strange turn when he encounters a mysterious entity that marks people with numbers, leading to their untimely deaths. Frank's attempt to understand and combat this threat draws him into a deeper mystery involving the spirit world.

During his investigation, Frank teams up with Ray Lynskey, a recent ghost, and his widow, Lucy Lynskey, who is a doctor. Lucy, initially skeptical of Frank’s abilities, begins to see the truth behind his unusual partnership with the spirits and the genuine danger they are facing. As Frank delves further into the case, he uncovers a sinister plot that ties back to a series of deaths stretching many years into the past. His journey forces him to confront his own demons and the unresolved grief over his wife's death, challenging him to use his powers for a greater good beyond his self-serving schemes.