The series is based on a story published in the New York Magazine, in November 2018 called 'The Watcher'. It chronicled a New Jersey family, The Broaddus, who was being stalked by a mysterious person who kept sending them letters.
In June 2014, Derek Broaddus and his wife, Maria Broaddus, were preparing to move into their six-bedroom home at 657 Boulevard in Westfield, New Jersey. Just before moving in, they received a letter in their mailbox, written in thick clunky handwriting addressed to 'The New Owner'.
The letter began warmly by welcoming the new owners into the neighborhood. But things took a turn when the writer asked intrusive questions like, “How did you end up here?” “Did 657 Boulevard call to you with its force within?”
The writer claimed that 657 Boulevard had existed for over 100 years, being watched by generations in his family- his grandfather in the 1920s, his father in the 1960s and was now his turn.
The Watcher had apparently surveyed the family and was aware that the couple had three children, noting that it was a bad decision to renovate the house because they would make it unhappy.
The stalker didn’t reveal his identity but claimed that he could be one of the many people that drove or walked by their house. The letter ended with, “Welcome my friends, welcome. Let the party begin” and signed “The Watcher.”
The writer sent the Broaddus family three letters, and the contents were so threatening that they eventually sold the house and left after five years.
The identity of The Watcher has never been discovered, leading some people to speculate that the Broadduses pinned the mail themselves as a tactic to avoid buying the house for $1.3 million.