Episode #4.2 - S4-E2
Other mistake: There is a scene set in the basement of Thames House. It is one of the most secure buildings in the country, but has graffiti on the walls.
Episode #8.8 - S8-E8
Other mistake: Tariq has been tasked with finding hotel guests who share their surnames with American presidents. His computer screen is shown with the search in progress. The surname "Bush" appears twice (two presidents, but only one surname), and the counts for the two entries are different. In addition, the name "Truman" is misspelled as "Trueman." (00:28:15)
Answer: They no longer exist. The Military Intelligence groups first appeared at around the time of the First World War. MI-1 was the original directorate, MI-2 dealt with the Soviet Union and Scandinavia, MI-3 with Germany and Eastern Europe, MI-4 handled aerial intelligence gathering, MI-7 dealt with propaganda, MI-8 with communication intercepts, MI-9 with covert operations, MI-10 were the technical experts, MI-11 dealt with security issues out in the field and so on and so forth. All these departments have either been shut down or subsumed into the Security Service, informally referred to by its original designation of MI-5, the Secret Intelligence Service, referred to as MI-6, or GCHQ, the Government Communications Headquarters.
Tailkinker ★