Or why you should read the The Atrocity Archive, The Jennifer Morgue, The Fuller Memoranda, and The Apocalypse Codex, by Charles Stross.
It seems that a lot of geek culture is about taking nerdy things that people love and combining them with other nerdy things people love to make some new mashed up nerdy thing that people love. Think cats that are also batman. While many examples of this phenomenon are mostly fanservice and Internet memery, occasionally you get a really smart, really adroit combination that elevates the constitutive parts and becomes a wonderful new whole (termed the peanut butter cup phenomenon). The Laundry Files Novels are a great example of a well done geek cultural mashup that transcends its origins.
The Laundry Files novels are essentially Lovecraftian Horror combined with espionage fiction with a pleasant veneer of Geekery and satire about the absurdity of government bureaucracy. The premise of the series is that certain types of noneuclidian geometric functions attract the attention of extradimensional horrors with tremendous power. If these occult maths are performed perfectly, say with the aid of modern computer technology, the result is magic. If things go poorly, then said summoned extradimensional horrors chow down on the minds of anyone unlucky enough to get caught in the way. Trouble is that through a combination of advancing technology and human population growth, the world is becoming a more appetizing place for mind-eating space horrors meaning that a full on apocalypse, CASE NIGHTMARE GREEN, is imminent.
Of course all of this is beyond Top Secret.
In the United Kingdom the work of protecting the general population from extradimensional mind-eaters falls to The Laundry, a clandestine department of the British espionage world comprised of highly trained specialists and "volunteers" conscripted into the service for knowing too much. The hero of the books, Bob Howard, a geeky computer hacker who inadvertently nearly destroys an English town while programming a graphics engine, is one such conscripted volunteer. The series follow his rise through the ranks of The Laundry in a time when the entire outfit is preparing for CASE NIGHTMARE GREEN. In the early novels he is an IT guy and small time operative scurrying in fear of lower and middle management while he does his part. In later novels we see him as a middle manager and full-fledged agent as he fights to stop Armagedan and navigate the vagaries of advancement in the British civil service. Bob is a very fun character: a geeky, styleless James Bond analogue who is in a committed relationship and who worries about filling out his reimbursement forms properly as he fights cults devoted to extradimensional horrors.
And if that last sentence sounded at all entertaining to you, I'd recommend you check out these novels. They are smart, abstractly frightening, and just good dorky fun.
(Yes, I know the books have ghastly cover art...)