Slow Horses Season 6 concluded with a primary character appearing to take his final breath. A teaser for Season 7 shows Lamb mentioning Cartwright sending a postcard from "the afterlife".
Cartwright returns to the home of his late grandfather and collapses in the kitchen while deciding between tea or wine to woo Baker. The actors filmed a happy ending for Baker and Cartwright that was ultimately excluded from the final cut.
Filming took place in London and Walthamstow, with the production team choosing more public locations for upcoming scenes. The production team had to rewrite a sequence to accommodate the specific location.
Crew members replaced the glass of a real house so they could smash it during a scene. The production team filmed in a location that felt like a doll’s house and created a pipe for a specific scene.
Scenes included characters ripping each other apart, a character screaming in the faces of others, and a character hunting others relentlessly. Other filmed moments featured a character being hunted, a character stopping a villain, and a character engaging in a knife fight with a hitman.
The production team also filmed a long dialogue scene between two actors, a scene with supporting artists eating in a restaurant, and a scene where Shirley says "For Coe". Characters were also shown drinking for fallen horses in one sequence.
Writers Mark Denton and Jonny Stockwood produced a list of pedophile insults for the production. The production team did not film a scene where Lamb had eight shots.
