Star Kit Harington received training from an ex-SAS soldier, so he could believably play a former MI5 agent in this film.
Scenes on the streets of London had to be re-shot because buses with pictures of Kit Harington kept getting into the shot.
The film ends with a freeze-frame in a photo negative effect which is the same way each episode of the TV show ended.
Actor Kit Harington's primary reason for taking the role was to avoid being typecast in period pieces.