Principal photography, interior and exterior, took place entirely in Bulgaria.
Despite the high number of British actors in the cast, only two speak with their native accents: Steve John Shepherd and Sir Patrick Stewart. The rest use various American dialects.
Shawn King, who plays Nurse Byrnes, is the wife of producer Larry King.
"Deus ex machina" can be clearly read on the side of the copier repair van at the beginning of the movie, but instead of being the divine intervention plot device to save the protagonist, it's the device that sets the entire plot in motion.