Dominique "Mo" O'Brien is having a rough time. She wields a soul-eating bone violin (that's trying to take over her will) in the service of her country, things with her husband are on the rocks, there's a sudden plague of humans manifesting superpowers, and she's expected to do something about at least the latter with the help of her husband's ex's. On top of all that, CASE NIGHTMARE GREEN (the end of the world as we know it) draws inexorably near, and Mo's suffering from a seeming cultural invisibility as a woman of a certain age.
Annihilation Score stands out from the other Laundry Files in a few ways. Beyond the obvious change in narrator, The Annihilation Score doesn't follow the trend of parodying various well-known British spy novelists' work. Instead we have a novel lambasting the cultural treatment and expectations of women while Mo heads up a superhero team along with the now vampiric Mhari, the transitioning to Deep One Ramona, and Jim/Officer Friendly as a tag-a-long representing the London Police. On top of this all, Mo deals with keeping her soul out of her violin's grip, coping with her husband's inheritance of the full Eater of Souls package, and generally attempts to convince herself she is perfectly stable and not in the midst of a verywell earned nervous breakdown.
Is the book perfect in its goal? No, but it's a damn good showing, and fits right in as a Laundry Files novel. Personally, I found Mo's ranting asides directly to Bob a bit on the "unprofessional" side since this is "supposed" to be a memoir that doubles as training/reference material on this specific case, which really makes the included sexy bits seem a bit exhibitionistic. On the other hand, Bob's memoirs aren't exactly professional, though, unless he's destiny entangled with a BLUE HADES succubus agent, there's really very little in the way of sexy details shared.
I loved the referencing of the Bechdel test, and once they get past their rather legitimate concerns and fears regarding each other, Mhari, Ramona, and Mo (heavier weight on the "you can kill me" part than the "you have an intimate history with Bob" issue) are a power-team.
Going in it's important to be aware that Stross deliberately has given us unreliable narrators. The previous books have been from Bob's point of view, giving us what Bob experiences and is filled in on. Now we get a different point of view on some overlapping events, and they don't quite match up. For example, The Rhesus Chart gives us the impression that his marriage with Mo largely fell apart due to the events of that novel, The Annihilation Score shows that maybe things weren't running as smoothly as he thought.
I'm left wondering how Mo will develop going forward. Latent superpowers aside, we never really see her act without near total reliance on her violin. It's implied that she has some sorcerous ability, but when AGENT CANDID is called in, it was generally something of a nuclear option. Definitely interested to see her role in the Laundry post The Annihilation Score, and eagerly awaiting the next chapter in the build towards CASE NIGHTMARE GREEN