Note: This story contains spoilers from “Slow Horses” Season 6, Episode 2.
Every season of “Slow Horses” is based on a novel by author Mick Herron, but the show’s sixth season is the first based on two of his works. The season is, in many ways, an amalgamation of Herron’s 2019 novel “Joe Country” and his 2021 follow-up “Slough House.”
According to Gaby Chiappe, who stepped up as head writer in the wake of longtime showrunner Will Smith’s Season 5 departure, the decision to combine “Joe Country” and “Slough House” was largely a practical one.
“The decision was made before I came onboard,” Chiappe told TheWrap. “‘Joe Country’ is an amazing novel, but it would present quite a lot of challenges for filming. It’s pretty much all set in a snowstorm in Wales. Finding a snow window in which to shoot, I think, would have been really, really challenging. So I think that was part of the reason it was decided to combine the two.”
Once that decision was made, the hard part became choosing which elements of each book would survive and which ones would be left on the cutting room floor. While it might have made things easier on the “Slow Horses” team, they quickly learned that they could not simply skip over the events of “Joe Country.”
“When we started, we didn’t really know which book was going to absorb the other. What ended up happening was that ‘Slough House’ took on parts of ‘Joe Country,’ and we made them as organic as possible because the books are serialized. You can’t skip one of them. Important things happen in ‘Joe Country,’” Chiappe explained. “The challenge was trying to make them happen in a slightly more ‘Slough House’-y way.”
“There are definitely elements from ‘Joe Country’ which were brought in and which changed the ‘Slough House’ story,” the writer added. “It was a hard decision, but it did give us a lot, putting two books together.”
One of the advantages of combining Herron’s two novels made itself apparent to viewers at the end of “Slow Horses” Season 6, Episode 2, titled “Daddy Issues.” Believing that his mercenary father Frank Harkness (Hugo Weaving) has taken to hiding in his late grandfather’s countryside home, River Cartwright (Jack Lowden) raced over there with a tire iron and thoughts of vengeance on his mind. But he did not find Frank waiting for him.
He found Sidonie “Sid” Baker (Olivia Cooke).
The character made her long-awaited return to “Slow Horses” five seasons after she was shot in the head and presumed dead at the end of the Apple TV show’s second-ever episode. Viewers have long suspected that Sid’s “death” may not have been all it was sold to be and, sure enough, the character’s return plays a pivotal role in the plot of Herron’s “Slough House.”
By combining that novel’s plot with that of “Joe Country,” the “Slow Horses” team found themselves able to bring Cooke back one season ahead of schedule. Chiappe, for her part, noted that “Slough House” is her favorite of the two novels precisely because it features Sid’s return.
“It was amazing be involved in that, in bringing that character back and writing for Olivia Cooke, who’s so brilliant,” Chiappe said. “Sid gets such a small amount of screen time in Season 1, and yet you so remember her. Her presence lands so heavily. She’s so delightful and so funny and so ‘Slow Horses.’”
“She’s perfect, really,” the writer added. “Bringing her back was just brilliant.”
Viewers can look forward to learning more about the circumstances of Sid’s return, as well as how she survived under the radar all these years, when “Slow Horses” Season 6’s third installment premieres next week.
“Slow Horses” releases new episodes Wednesdays on Apple TV.
