Described as an anthology series, each season is conceived as a self-contained miniseries, following a disparate set of characters and settings, and a storyline with its own "beginning, middle and end".
In the first season, a family that moves to a house Los Angeles, unaware that it is haunted. Father Ben Harmon is trying to deal with his wife's rejection after he has an affair with a student, and soon falls under the house's sway. Meanwhile, wife Vivien must not only try to forgive her husband but deal with the aftereffects of a miscarriage. Daughter Violet is confronted with hostile girls at her new school and befriends her father's disturbed teenage patient, Tate Langdon. And lurking nearby is neighbor Constance, a former actress who both hates and is oddly protective of her special-needs daughter Adelaide, who can sense the house's evil.
In the second season, strange happenings occur at Briarcliff Manor, run by the Catholic church as a sanitarium. Sister Jude administers the facility with a strict hand while concealing her lusts. Dr. Arthur Arden conducts strange experiments on the patients, including accused serial killer Kit Walker, the infamous Bloody Face, who may or may not be innocent.