Re: Sounds like the basis for Evelyn Waugh's other novel...
...Then, the Actual Agency, that do the real high flying stuff. Stuff that you *would* be killed if you found out about....
Alas, this bit doesn't actually exist. It is made up by the other, far more powerful and secretive section, which you don't even cover in your item.
This is the Budget section, which is tasked with maintaining the existence and budget for the Security and Intelligence services, even though WW2 and the Cold War (which originally provided the justification for their existence) have now long since finished...