This is a sequel to "The Atrocity Archives". That universe, or at least Bob Howard's part of it, is a delightful mix of Lovecraft, Brazil, and The IT Crowd. The book I read also contained "Pimpf", a short story set in the same universe, and "The Golden Age of Spying", an essay that delves into some of the history of James Bond.
The Laundry is a secret British government agency that tries to keep Earth, and humanity, safe from the creeping horrors from neighboring dimension that are always scratching at our metaphorical, or metaphysical, door. You see, all it takes is one incautious mathmetician trying to prove the wrong hypothesis and the next thing you know there's Nyarlathotep running rampant sucking out people's brains.
Bob Howard, IT support and occasional field agent, is sent out to investigate the activities of Billington. Billington, a classic multi-billionaire Evil Villain, has set a Hero Archetype geas, which protects him from anyone who doesn't fit the Archetype, in this case James Bond. The geas is a destiny-entanglement spell, its core material component is a mock-up model of the ships involved, with dolls and a bunch of James Bond paraphernalia. It's meant to keep everything running along Billington's desired path; his plan is to short it out just before the ersatz Bond can fulfill his function.
Bob's management are well aware of this, and after binding Bob to a demon-bound Deep One, send him in (with little explanation) and try to manipulate events to work through the geas. His management chain, headed by the enigmatic Angleton, isn't precisely evil, but is ruthless. After all, defending humanity against ultra-powerful, inimical other-dimensional entities really is a no-holds-barred fight.
While I enjoyed it, and liked several of the twists, the story didn't quite work for me. It was a rather complex set-up, and I didn't always follow, or buy into, the motivations of the various actors. It's possible that stylistically, he was going for the feel of the Bond books; I can't really say, as I've never read the originals.
Overall, my take is that if you liked "The Atrocity Archives", you should probably give this one a try. If you haven't read "The Atrocity Archives", try that one first.
"Pimpf" is a short story set in the same universe. In it, Bob's new intern runs afoul of Bob's NeverWinter Nights demonologist honey-pot. Having spent years as an avid NWN player, I probably should have enjoyed the virtual-reality part of this much more, but overall, the story just came across as muddled.
If you're interested in Bond, this piece may be worth getting the book all in its own. It's only 13 pages long, but I found it both informative and amusing. It goes into the history of the Bond universe, and also Ian Fleming's background. He give a pretty good argument that Bond is a Mary-Sue, living out his dream of working in the field. Ian Fleming worked in intelligence during WWII, but in a desk job.
It also has a quite amusing long "interview" with Mr. Blofeld, the head of SPECTRE. Why, they were just venture capitalists specializing in disruptive new technologies, not criminals!