A skilled computer programmer learns that electronic intelligences - computers - are attractive of other supernatural intelligences. At least some of the intelligences are similar to the Elder Gods of Lovecraft's writing. The spy agency involved first met above a laundry. The first few books are an introduction to the problem and characters and are Cthulhu meets James Bond meets The Office. Later, the bureaucracy snafus fade and the horror digs in.
I post on the subject today because tomorrow, another book in the series is being released!
Wikipedia on The Laundry Files
A reading order or timeline
Book launches for the Labyrinth Index
The Labyrinth Index on Kindle, available August 30!