Season 6 of Slow Horses is coming, and it brings a fresh wave of faces alongside the familiar ones. The Emmy and BAFTA-winning spy drama returns with a cast guide that treats the show’s comeback as a reason to brush up on everyone involved — both the new arrivals and the old hands who have been away.
The returning cast includes Jackson Lamb (Sir Gary Oldman), Diana Taverner (Kristin Scott Thomas), River Cartwright (Jack Lowden), Catherine Standish (Saskia Reeves), Louisa Guy (Rosalind Eleazar), Roddy Ho (Christopher Chung), and J.K. Coe (Tom Brooke). A few returning actors now carry larger roles alongside a handful of newcomers: Lenny Rush, Kyle Soller, MyAnna Buring, and Harry Lloyd.
Sid Baker Returns After Years Away
The guide lays out everything viewers need to recall about Sidonie “Sid” Baker before she returns in Season 6. She was last seen in Season 1, and fans believed she had died. Among the Slough House agents coming out of hiding as the group faces pursuit is Sidonie, played by Olivia Cooke.
Since Cooke’s last appearance, she has kept a full schedule, adding more than 30 film and TV credits to her resume. That list includes A Talent for Murder, House of the Dragon, The Girlfriend, Ready Player One, Bates Motel, and Sound of Metal.
Reece Nesmith Slayed Viewers With Sass
Decider’s full Season 6 review calls Lenny Rush “the show’s newest standout star,” playing Reece Nesmith, a young witness to a murder with unexpected sass and expert comedic timing. The guide notes that Rush has nearly 20 film and TV credits, including Am I Being Unreasonable?, Enola Holmes 2, Doctor Who, Dodger, A Woman of Substance, and The Dumping Ground.
Instagram is where fans can keep track of Lenny Rush beyond Slow Horses, following him at @mrlennyrush.
Jim and Jane Hunt the Slow Horses
The guide holds off on revealing the full story behind two assassins who joined the hunt for the Slough House agents until later, instead choosing to focus on the actors themselves. One of those assassins is played by Kyle Soller’s Jim and MyAnna Buring’, who takes on the role of Jane.
Soller has appeared in a long list of popular TV series and films, such as Death by Lightning, Andor, Anna Karenina, The Titan, and Poldark. Buring, an actor and writer, has built up more than 70 film and TV credits, among which are The Witcher, The Twilight Saga: Breaking Dawn Parts 1 and 2, Doomsday, Kill List, The Descent, Ripper Street, and Downton Abbey.
For more information, follow Kyle Soller and MyAnna Buring on Instagram using their handles @kyle_soller and @myannaburing.
Emma Flyte Steps Up Her Game
Ruth Bradley is back as Emma Flyte, and the guide calls it her finest season yet. The character first appeared in Season 4, and she has since grown into an essential part of the Slow Horses team. Now, in Season 6, the guide says it is wonderful to watch her take on a larger role.
Ruth Bradley boasts a large body of work across film and television, with more than 50 credits to her name. Her resume includes roles in Ted Lasso, Humans, Love/Hate, The Gold, Concordia, and The Innocence Project. To stay up to date with her latest projects, follow her on Instagram at @ruthbradley24.
Damien Cantor Visits MI5
Harry Lloyd joins Season 6 as Damien Cantor, the owner of a right-leaning British news channel who visits MI5 in Episode 1. The guide notes that with Peter Judd in his corner, Damien doesn’t have the purest intentions, and Diana hasn’t seen the last of him.
With over 60 film and TV credits to his name, Harry Lloyd has appeared in Prime Target, Anthropoid, Jane Eyre, The Theory of Everything, The Iron Lady, Counterpart, Manhattan, Game of Thrones, Robin Hood, and The Fear. You can follow him on Instagram at @mrharrylloyd.
Peter Judd’s New Partner
Peter Judd, the right-wing politician played by Samuel West, returns for Season 6, full of confidence, with a new partner in crime named Damien Cantor, and a drive to take charge of Diana. West earns instant dislike in Slow Horses, yet he has a cherished screen persona built from over 100 film and TV credits, among them Howards End, Van Helsing, Darkest Hour, All Creatures Great & Small, The Dark Is Rising, Mr Selfridge, and many more.
Moira Tregorian May Be on the Hit List
Moira Tregorian, the MI5 admin worker played by Joanna Scanlan, makes a comeback this season. A scene from the trailer reveals a mysterious substance being sprayed on her, which suggests she might also be on the Slough House hit list. The guide’s verdict: hate that for her, but love that we’re seeing more of Scanlan this time around.
Among his many screen appearances, Scanlan has picked up more than 100 film and TV roles. These include The Thick of It, Big School, Getting On, Puppy Love, No Offence, Requiem, The Larkins, Riot Women, and Hold the Sunset.
Lucian Msamati Joins the Team
Lucian Msamati’s Oliver Nash is Chairman of the Limitations Committee, which oversees MI-5 and thus Diana’s desk. In the Season 6 teaser, Oliver is shown saying, “No one is unac,” though the guide cuts off the quote there.
Comparing the Returning Actors
A group of actors with substantial credits in both television and film make up the returning cast. Below is a look at how their careers compare:
| Actor | Role | Credits |
|---|---|---|
| Olivia Cooke | Sidonie “Sid” Baker | 30+ |
| Ruth Bradley | Emma Flyte | nearly 50 |
| Samuel West | Peter Judd | over 100 |
| Joanna Scanlan | Moira Tregorian | over 100 |
Key Facts Box
- Season: 6
- Returning actors: Sir Gary Oldman, Kristin Scott Thomas, Jack Lowden, Saskia Reeves, Rosalind Eleazar, Christopher Chung, Tom Brooke
- New additions: Lenny Rush, Kyle Soller, MyAnna Buring, Harry Lloyd
- Old faces back with elevated involvement: Olivia Cooke, Ruth Bradley, Samuel West, Joanna Scanlan
- Credits: Olivia Cooke — 30+; Ruth Bradley — nearly 50; Samuel West — over 100; Joanna Scanlan — over 100
The cast guide delivers on its promise by introducing fresh faces while reminding viewers of the returning ones. Whether that makes it worth watching remains an open question.
Source material: “‘Slow Horses’ Season 6 Cast Guide: Meet The New Players In ‘Slow Horses’ Strange, Strange Game,” Decider.
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