Robert Sedgwick, who plays serial killer Oleg, is Kevin Bacon's brother-in-law, being Kyra Sedgwick's younger brother.
Scenes at the party were filmed at Coe Hall, a "Great Gatsby" type mansion on the North Shore of Long Island.
The geo coordinates that Theo and his sister discover after "breaking" the passcode in order to find a mysterious contact of Theo's mentor, do not pinpoint an estate property in Annapolis, MD, but rather 30 Schenck Avenue in Beacon, NY, which is definitely not an estate neighborhood.