The first two volumes in the Laundry Files series by Charles Stross are something of a whimsical blend of spy novel and Lovecraftian horror. While the protagonist Bob Howard is often in danger, sometimes mortal and sometimes immortal, Howard's voice is cynical in the world-weary way of the British. The otherworldly horrors that Howard faces seem somehow mundane as he gathers himself up to fight them. Part of the whimsy also derives from the satirical nature of Howard's down time; when he is not fighting Elder Gods, he has to wade through ribbons of red tape and mounds of paperwork because he works for a government agency. And Howard makes it clear that the penalties for not performing to bureaucratic standards—did you log in the number of paper clips you used?—are just as deadly, if not more so, than Cthulhoid horrors intent on taking his soul.
The Fuller Memorandum, the third book in the Laundry Files, is subtly different. Stross allows the bureaucratic fumbling to move into the background of his story, and instead focuses on the human cost of the very real and impending invasion by extradimensional horrors. There is very little whimsy, even though Howard remains stoically cynical; instead the novel begins with a gruesome accident in the field and grows to supernatural dread. Along the way Stross moves the story more clearly into the realm of Lovecraft by invoking the best definition of horror—man fighting against enemies he cannot overcome. Stross drives this perspective home with Howard's meditations on how he wishes he could be an atheist, but he has actually seen the gods and is terrified of their return.
When Howard is sent out to an air museum in the British countryside to exorcise an old haunted airplane, he momentarily takes for granted the apparent ease of his mission, only to see an innocent bystander arrive at exactly the wrong time and die a horrible death, an image that haunts Howard through the rest of the novel. This opening scene sets up a crucial difference between this novel and the others, a difference that adds to the real horror that underlies the novel: humanity's real danger in the current crisis is not the impending invaders from another dimension so much as people themselves. Whether through weakness or incompetence or active belief, it's human nature that is most likely to open the door to the invaders, not anything that the invaders can do themselves. This point is emphasized while the novel's plot rounds into shape, as Howard is pursuing a mole inside the agency created to thwart extradimensional incursions. Again, it is not Deep Ones or Nyarlathotep that he must face down; it is someone that supposedly works with him in the fight against the aliens.
Eventually Howard's wife is endangered as is his immediate supervisor and mentor. And in order to bring the mole into the open, Howard somewhat unwillingly sets himself out as bait in an elaborate trap. But again, human forces are more malign than the supernatural, and mistakes lead to his capture and a potential fate far worse than death. In short, Howard finds himself in the hands of a cult that intends to use him as a portal to bring one of the great gods of the Cthulhu pantheon to Earth.
The Fuller Memorandum brings into sharp focus another axiom of the genre, that a horror is proportionately more terrifying the more closely it takes on human attributes. Consider the current fascination with zombies in movies and books and TV shows like The Walking Dead. What makes the dead returning innately scary? I would argue that if Aunt Hilda rose out of the grave tomorrow and looked and acted as she always did—no unquenchable hunger for brains in this example—we might be somewhat appalled but not terrified. What is terrifying is that it's not Aunt Hilda; it's a monster that has taken her form. It has enough likeness that we can see what used to be Aunt Hilda but it is actually something else, something we want to be able to trust but will kill us if we do. Alien possession movies use this same paradigm; The Invasion of the Body Snatchers is horrible because they aliens are taking our place, looking and acting like us until it suits them not to. And then we die. Alien looking horrors can be plenty scary, but they lack the qualities that incline us to trust them, so the horror of trust betrayed cannot come into play.
The Laundry novels have relied on the fear of the unworldly, stoked to a fever pitch by H.P. Lovecraft and his followers until it is almost cool to know what Cthulhu is and share a joint shudder at the mention of his name. But with The Fuller Memorandum, the horror takes that one extra step—Howard is fighting people, people that he may well know. And they are capable of truly atrocious actions that endanger him and his loved ones. Nothing is more frightening than people turned to something else.
As always, Stross's work is thought-provoking and fun, but it really is a delight for him to turn what could have been considered a "fluff" series into something darker. The dark humor of the earlier books is still there but it is a companion to a horror strain more vibrant than in previous books. If a reader would like to just jump in to the series cold, The Fuller Memorandum makes references to the earlier books, but knowledge of them isn't necessary to appreciate it. But I'm pretty sure reading just one is going to lead to wanting to find the others as well.