Slow Horses Head Writer Promises Not to Kill Favorite Characters Unless Mick Herron Does

Since premiering on Apple TV in 2022, Slow Horses has remained one of the most reliable shows on streaming. The adaptation of Mick Herron’s Slough House spy novels packs each six-episode season with tight mysteries and sharp humor targeting failed MI5 agents. Apple has delivered six seasons in four years, avoiding the massive delays plaguing many hit series. When creator Will Smith announced his departure after season 5, fans worried about the future. Gaby Chiappe felt that pressure most acutely when she stepped in as head writer for season 6.

“I was a massive fan of the books and a massive fan of the series, so you really don’t want to screw that up,” Chiappe tells Polygon. “It’s not just professional pride, it’s also my favorite show. It felt like an amazing opportunity and quite scary in equal measure all the way through.”

Quality remains high during one of the most complex seasons yet. Previous seasons adapted a single Slough House book each, but season 6 combines Herron’s sixth book, Joe Country, and his seventh book, Slough House. The team made that choice before Chiappe joined.

“Joe Country is an amazing novel, but it essentially takes place in a blizzard in Wales over a very short time,” Chiappe says. “Finding somewhere you could film that snow presented really big challenges. In lots of ways it’s a very exciting novel, but it’s one chase in one weather condition.”

Herron’s mysteries reach individual conclusions while building on one another, meaning the show could not skip Joe Country. Chiappe incorporated key plot points, including River Cartwright (Jack Lowden) having an unhappy reunion with his mercenary father, Frank Harkness (Hugo Weaving), at his grandfather’s funeral.

“In the end, it felt more like Slough House with some elements of Joe Country changing the shape of Slough House,” Chiappe says. “I hope we’ve made it feel seamless and organic, because we were trying to take the best of both and make them into something that would feel like a proper arc of its own rather than something that was grafted together.”

Making a pact with the audience

Frank returns alongside other familiar faces in season 6. Sid Baker (House of the Dragon star Olivia Cooke) comes back after being presumed dead following a gunshot wound to the head in season 1. Louisa Guy (Rosalind Eleazar), who quit Slough House at the start of season 5, also returns. Louisa’s departure originated from scheduling conflicts rather than the source material.

“Very occasionally there’s a change like that which isn’t in the books, but we wouldn’t kill somebody who isn’t killed in the books,” Chiappe says. “You have to be flexible, but we’re not deviating from the novels for the sake of it.”

The rapid release schedule meant writing for season 7 began while season 6 was still filming. Co-executive producer Billy Bowring coordinated with Chiappe and Ben Vanstone, who takes over as showrunner for season 7, to manage the transition.

“As a viewer, even a year feels like a long time to wait, but knowing that you’re going to get the next season in the autumn some time, and they’re going to keep coming is really good,” Chiappe says. “There are shows where I loved season 1, and then you wait for ages for season 2, and then you’ve sort of lost a connection with it. We’re making a kind of pact with the audience that you will get the show this time next year.”

Season 6 of Slow Horses premieres on Apple TV on Sept. 16. New episodes release Wednesdays through Oct. 21.

Source: Polygon