John/Simon (2011) HD online
|Tony Cook||-||John / Simon|
|Lori MacFadyen||-||Becky Morris|
|Tony Fordham||-||Tony Chapman|
|Daniella Pellegrini||-||Lucy Mounter|
|Marcus Ako||-||Harry Foreman|
|Sarah Hough||-||Katie Nomad|
|Dani Russell||-||Chelsea Pollard (as Natasha Danielle)|
The original script had the events take place in a doctors surgery, but it was changed to an empty house to make it feel more claustrophobic.
An avid Doctor Who (2005) fan, director Sophie Langford wanted in include a reference to the show in the script, and chose the line from the last episode starring David Tennant as the Doctor, when he says "I don't want to go". The line was incorporated into the script and used when Simon is trying to defeat John at the end of the film.