: Dean meets with a local private investigator, Theodora Birch, who reveals the chilling history of a previous owner named John Graff. In 1971, Graff allegedly murdered his entire family in the house after receiving letters from "The Watcher," claiming he was doing it to "purify" the home.

: The letters often mention the "young blood" of the family, suggesting a motive rooted in envy of the Brannocks' perceived wealth and vitality. Cast and Characters in Episode 3

(Mia Farrow): The eccentric neighbor who seems to know more than she lets on.

(Noma Dumezweni): The private investigator providing crucial historical context.

(Bobby Cannavale): The increasingly erratic father determined to protect his family.

: Dean’s descent into obsession mirrors that of the alleged John Graff, raising questions about whether the house itself exerts a dark influence on its owners.