The series is set in the English countryside in 1888, and centers on Nathan Appleby, a gentleman farmer who is obsessed with proving the existence of the afterlife. Appleby investigates hauntings, paranormal happenings, and ghostly visitations, encouraged by the Society for Psychical Research. Soon his interest in the occult poses a threat to his family, his livelihood and his sanity.
After a young boy is disturbed by some terrifying visions, Nathan attempts to do everything he can to protect him. Nathan has been having visions of this own though and he could be on the edge of madness.
It is Somerset 1894 and after a pioneering Victorian psychologist brings his vivacious young wife to live on his family's estate, he is confronted by one disturbing case after another.