Olivia Cooke Teases Sid-Diana Showdown in Slow Horses

Olivia Cooke has returned for season 6 of Slow Horses and wants a showdown with Kristin Scott Thomas's character Diana. The season 6 finale, titled 'Judgement Day,' releases on Apple TV on October 21, delivering the long-teased confrontation between Sid and Diana Taverner. It resolves a central tension from the series' run. Sidonie Baker was originally introduced in the first season, exhibiting flirty chemistry with River Cartwright before dying from a gunshot wound. Her resurrection after a four-season absence was not a surprise to fans familiar with Mick Herron's novels.

The finale follows Sid and River through a harrowing night evading Russian sleeper agents. Their journey takes them from River's late grandfather's country house to Diana's beach retreat, which Jackson Lamb appropriates as a safe house. They travel through a barn and an arcade to an airstrip. There, Sid is nearly shipped off to Russia as an unwilling sacrifice. The safe house becomes unsafe as Lamb and Taverner finally join forces. Two Russian assassins are hot on their tail.

MI5 leader Diana Taverner used Sid's identity as a cover for an off-the-books assassination on Russian soil. This Kazan operation prompted the Kremlin to seek revenge, compromising the safety of all Slough House agents. Lamb learned about the operation and was after Diana for putting his agents at risk throughout the season. She refused responsibility. Sid clings to Diana because she believes Diana saved her by getting her out of the hospital and into specialized rehab. She experiences a form of Stockholm syndrome, viewing Diana as collegial.

River sacrificed himself to stop Sid from boarding the plane in the previous episode. His fate remains a highly anticipated point in the finale. Sid and River share a first kiss on the airstrip before River collapses from apparent poisoning in the kitchen. The finale will feature a high-stakes, action-packed showdown. Head writer Gaby Chiappe teased more deaths in the finale, following the shocking death of JK Coe earlier in the season.

The Physical Toll and On-Set Reality

Cooke endured demanding stunt work for the season. She pulled both quad muscles badly while running alongside Jack Lowden at 2 a.m. during a scene where they were chased by a Land Rover. She was hobbling around for two weeks after the injury. Cooke found the barn sequence scary due to the presence of large cows that can kick. In contrast, the truck and exploding oil drum sequence was a fun, cathartic 'Jason Bourne moment' for her.

Cooke had to remind herself of her accent to reassume the role of Sid after years away. She and director Adam Randall discussed Sid being in a rehabilitation facility kept under wraps by MI5, possibly in Cumbria. Cooke described working with Jack Lowden as wonderful. "He chucks curveballs and is very funny and doesn't take it too seriously," she said. She loved the night shoots and Adam Randall's run-and-gun energy on set. The set felt like the best high-school reunion possible due to reuniting with the same crew from House of the Dragon.

Kristin Scott Thomas and the Path Ahead

Olivia Cooke praised her potential adversary. "I want a showdown with Kristin Scott Thomas for myself and my diary," she said, calling it a cathartic thing that must happen. She described Scott Thomas as a wonderful actor she could watch endlessly. Cooke had not read the Mick Herron novels prior to returning but read the source material for the season she was about to film because she was sure she was coming back.

The future of the series is secure. Season 7 is already confirmed and will adapt Mick Herron's novel Bad Actors. Season 8 has also been renewed and will be based on Clown Town. The show was created by Will Smith and stars Gary Oldman as Jackson Lamb, alongside Jack Lowden, Saskia Reeves, and Rosalind Eleazar. Other Slough House agents include Shirley Dander, played by Aimee-Ffion Edwards, and Roddy Ho, played by Christopher Chung. Cooke herself wants to do theater and be on the other side of the camera after House of the Dragon. The season 6 finale on Apple TV features the safe house showdown she teased.