... sshhh!!! this is a secret ...

James Bond worked for MI6: Military Intelligence - Department 6. Overseas Operations.
MI5 Military Intelligence - Department 5. Home intelligence.

Presumably there is an MI1, MI2, MI3 and MI4

What do they do???

I reckon MI5 and MI6 are really front organisations that people know about and that MI1 to MI4 does the real spying.

Paranoid thought If this is true I could be doomed. If the Odtaa Files suddenly disappear please report to all conspiracy theorists, left wing newspapers and liberal politicians that everything they thought about the state is true. Don't tell the police or you will be doomed and will be made to disappear - also.

(I know also is grammatically incorrect here, but ..... I like it)