SLOW HORSES by Mick Herron. First of a series of (checks Wikipedia) five novels and two novellas.
Here’s the deal. The Security Service, known popularly as MI5, sometimes can’t outright fire people. Political reasons, operational reasons. But it would still like to get rid of them. So it puts them in Slough House, a dismal set of offices intended to make those consigned there so miserable that they just quit. Those people are known as slow horses. Slough House, slow horse. Slough House is run by Jackson Lamb, himself a slow horse of mysterious provenance, an impressively offensive creature who looks a bit like Timothy Spall if you stuffed Timothy Spall with old pork fat and left him out in the rain for six weeks.
(Side note: Herron “casting” Lamb as Timothy Spall is, in its own way, as devious as Jeffrey Deaver describing Amelia Sachs in THE BONE COLLECTOR as an impossibly hot actress/supermodel, thereby creating the space for the inevitable casting of Angelina Jolie in the film version.)
Herron likes an odd name. The lens for the book is a new slow horse called River Cartwright, for example. Herron enjoys himself immensely with names, and also details. The one thing you’ll take away from this book is that Herron is writing only to amuse himself, and having a whale of a time doing it. The twists and tangles of the plot, involving right-wing extremists and about twenty bad choices, propelled me through the book at quite a clip, but I always paused to admire the amount of fun Herron was having. Boris Johnson, or a legally deniable version thereof, shows up halfway through, pretty much note-perfect, and he’s there largely so Herron can hate him.
It’s got a big crowd-pleasing third act, the complex weave of plot threads is handled very well, and it’s basically an extremely skilfully tailored entertainment. If you ever liked a spy novel or a crime novel, you’re going to kick back with this, have a good time and wonder why it’s not on tv with Timothy Spall.