The set used for the FBI is the same as the one used for "Bones", another series on Fox.
The storekeeper tells Langton, "I didn't see who wrote the note - it could have been any one of them. There was a bit of a mishegoss going on up at the front of the store at the time." "Mishegoss" is a Yiddish word meaning "craziness."
Angus Sutherland, who plays Ilya, is the son of Donald Sutherland. Donald Sutherland was in the Buffy the vampire slayer movie-- another Joss Whedon project.
Brian Bloom (Jonas Sparrow) and Amy Acker (Claire Saunders) previously costarred on the short-lived FOX drama 'Drive'.
The cult leader uses the fake name "Jonas Sparrow." Steve Martin plays a con artist posing as a revival preacher named Jonas Nightingale in the film Leap of Faith (1992).