Look, I'm just a lad from an irish country village sometimes I have to admit that the subtleties of the British class system and its cultural affect are a bit beyond me. You have the upper class chaps from the private schools, and then you have the unnamed agent, who is not upper class and did not go to a private school, yet he's the biggest snob you'll encunter on these pages, with his elegant good taste in clothes, coffee and food. Unnamed agent, of course, is a young person in swinging London, so maybe he's just at the heart of the zeitgeist while the stodgier old British institutions endure in mouldering but unshifting implacability. Unnamed agent keeps bothering people about expenses and back-pay, maybe that's the real difference. 

Anyway, British boffins are leaking and defecting in weird numbers, and being kidnapped and put up for sale, Unnamed Agent is transferred to a slightly different department to help look into it, and things get very complicated from there. Pay attention, now, and it'll all make sense.