Slow Horses (Slough House Book 1)

My cousin—a reader with great taste—has been telling me to read this series for over ten years, but it wasn't until Will and I started watching the Apple TV series that I actually did. The series is now nine books strong, and I decided to start at the beginning. Slough House isn't a house, and it's not in Slough, but it's so far away from MI5 headquarters it might as well be. It's where MI5 rejects (known as "slow horses") get sent instead of being fired—not out of any sense of mercy, but because legal proceedings are a real hassle; the hope is they'll find Slough House so unpleasant they'll quit. Season 1 of the Apple TV series is based on this book about an MI5 black op: because I was familiar with the loose outline of the plot, I could focus on Herron's excellent writing, particularly the greater internality of the characters, the heightened nuances of their relationships, and the greater depth to their backstories.