Is Andrew telling the truth, or is he just another piece of the puzzle designed to scare the Brannocks away? Episode 2 doubles down on the eccentricity of the neighbors:

Blog Post: "Blood Sacrifice" — Peeling Back the Layers of The Watcher Episode 2

Their bizarre behavior and lack of boundaries make them the primary "cult" suspects.

Is there really a blood cult in Westfield, or is Dean being manipulated by a master puppeteer? Let’s discuss in the comments! 'The Watcher' Season 1, Episode 2 Recap: 'Blood Sacrifice'

The honeymoon phase of 657 Boulevard is officially dead. In the second episode of Netflix’s The Watcher , titled the Brannock family moves from "unsettled" to "unhinged." If you thought the first letter was just a prank, this episode introduces a chilling lore that suggests the house might be more than just a piece of real estate—it might be a feeding ground. The Descent into Paranoia

Andrew claims he witnessed neighbors in red robes performing a "blood sacrifice" around a baby.

The letters eventually drove his wife to suicide, leaving him a broken man warning Dean to "get out while he can." Suspects Everywhere