
It took me awhile, but I eventually got taken in by the Slow Horses series on Apple TV. And, after getting caught up with that, I decided to check out this first book in Mick Herron's series. (On which the first season of the TV show is based.)
As it turns out, the TV show is a remarkably faithful adaptation of the book. It's a mixture of very dark humor, violence, cynicism, betrayal, and suspense. Mick Herron is a skillful, stylish writer; I found myself smiling every few pages at some deftly executed sentences.
Summary: Jackson Lamb is in charge of "Slough House", an island of misfit MI5 spies. It's where agents who have screwed up badly get sent, a dead-end posting designed to get them to resign. Lamb helps in that effort by being abusive to his charges, reminding them at every opportunity of their worthlessness. The newest arrival, River Cartwright, was set up to fail by a rival spy… or was there something else going on? In any case, he's now relegated to sorting through mounds of disgusting garbage, retrieved from the bins of a disgraced right-wing journalist. And (of course) finding nothing.
Ah, but could there be a connection with a fanatical, even more right-wing, group who have abducted a Pakistani student/stand-up comic, promising to decapitate him on video in a couple days? (Spoiler: yes.) And will the Slow Horses be involved in all this. (Also yes.)
There are some changes; for example, book-Lamb does not lip-sync to the Proclaimers' "500 Miles". You'll have to watch the show for that. And you should, it's hilarious.