- Defictionalization: Some terminology and catchphrases invented in this series are now used by the real MI-5.
- Enforced Method Acting: Richard Armitage was actually "waterboarded" for a Flash Back scene, as a desire for Method Acting. The screams were genuine.
- Fake American: Understandably, quite a few of the CIA personnel depicted on the show are played by British or Irish actors. In fact, Megan Dodds is notable as an aversion of this by being an American-born actress (albeit one who had been living in London for about five years at that point) playing CIA liaison Christine Dale.
- Promoted Fanboy: Geoffrey Streatfield is a long-time fan of the series, and viewed his role in the tenth series as "a dream role".
- Romance on the Set: Raza Jaffrey married co-star Miranda Raison in 2007 and then Lara Pulver in 2014. He has a son with the latter.
- Screwed by the Network: The two cable runs in the US. See the trope entry for more.
Trivia / Spooks