The Atrocity Archives by UK Author Charles Stross.

In Hugo and Nebula Award winner Stross?s series, Lovecraft's Cthulhu meets Deighton's and Flemming’s spies with often hilarious results; the author mixes the occult and the mundane, the truly weird and the petty. Bob Howard is a computer übergeek employed by the Laundry, a secret British agency assigned to clean up incursions from other realities caused by the inadvertent and sometimes deliberate manipulation of complex mathematical equations: in other words, magic.  Bob finds himself promoted to fieldwork after he bravely saves the day during a routine demonstration gone awry. His first mission nets a beautiful Physicist named Mo and news of a plan by terrorists to open a rift in our universe.  Now Bob, Mo’ and a specialized SAS unit are all that stands between the Earth and a powerful ancient demon seeking to enter our universe to suck it dry.  Men in Black meets the UK Office.  Complete series is under option.  Seeking development and packaging.
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