If you’re already swept up in the Emmy-winning phenomenon that is Slow Horses , you know that each season of the Apple TV+ hit follows a different book in Mick Herron’s series about a group of misfit M15 agents. Slow Horses Season 5 (which premiered on Sept. 24) is based on London Rules , which covers the suspenseful, twist-filled investigation into a string of terrorist attacks that have a surprising connection to the underdog unit.

Want to take a peek ahead at this season’s mystery? Here’s the London Rules book ending and plot summary, explained.

A Violent Pattern

London Rules begins with a mass shooting in a small English village. Soon after, more violence occurs, including the bombing of a zoo penguin enclosure and an attempted explosion on a train.

At the same time, it

See Full Page