I don't know how many have seen the movie by the same name (I haven't), but I just read all three books in this trilogy. I have a copy of the Swedish version of the movie; just haven't watched it yet. Pretty fascinating stuff, related to real-life events. The series explains how it's possible for a rogue group within the Swedish version of the CIA to promote an evil agenda in the name of "national security". (Or, by association, how it could happen in the USA).