Played by: Colin Firth

In 2011’s heady, dense spy flick Tinker Tailor Soldier Spy, British Intelligence must find the identity of a Soviet spy in its midst during the height of the Cold War. After trudging through a tightly-weaved mystery, we find out that the spy is none other than Bill Haydon, one of the agency’s most trusted members. It’s not shootouts or action scenes that land Haydon on this list, it’s the cat-and-mouse game of espionage that makes him so dangerous.

Where most communist villains in movies are of the over-the-top variety, Haydon captures the atmosphere of paranoia during the Cold War in a realistic way. It’s not even until the film’s ending when you finally realize what has been going on the whole time, and it proves that deception is the most dangerous villain of all.