Slow Horses season 4: Release date, cast, plot, and everything we know so far

Given the popularity the British spy thriller has amassed since it premiered on April 1, 2022, there’s no way the story ends with season 3. Slow Horses season 4 was confirmed alongside the third installment in June 2022, even before Dead Lions, the second season’s debut on December 2, 2022.

Similar to the previous three installments, the fourth will also follow the original source material, which is the fourth book of Mick Herron’s Slough House series, titled “Spook Street.” After Apple TV greenlit the third and fourth seasons, both installments were filmed consecutively in London. Follow along with the article to learn more about Slow Horses season 4.

---

Slow Horses season 4 will debut on Apple TV+ on September 4, 2024

Slow Horses season 4 will be released on September 4, 2024. It will be directed by Adam Randall, who is known for helming I See You 2019, Night Teenth 2021, and iBoy 2017.

The new season will also see five fresh faces, including Hugo Weaving and Ruth Bradley. Although not much has been revealed about the upcoming installment, it is expected to run for six episodes, based on the usual pattern.

As stated above, season 4 will be adapting the fourth book, and here’s how the official synopsis of it reads:

"What happens when an old spook loses his mind? Does the Service have a retirement home for those who know too many secrets but don’t remember they’re secret? Or does someone take care of the senile spy for good?"

It further says:

"These are the questions River Cartwright must ask when his grandfather, a Cold War–era operative, starts to forget to wear pants and begins to suspect everyone in his life has been sent by the Service to watch him."

It ends with:

"But River has other things to worry about. A bomb goes off in the middle of a busy shopping center and kills forty innocent civilians. The agents of Slough House have to figure out who is behind this act of terror before the situation escalates."

Surprisingly, Slow Horses season 5 also got confirmed, six days after the third season ended. The fifth installment will adapt the fifth book, titled London Rules.

---

Slow Horses season 4 cast and characters

Every major cast member will be returning to the fourth installment to reprise their respective roles once again:

• Gary Oldman as Jackson Lamb
• Kristin Scott Thomas as Diana Taverner
• Jack Lowden as River Cartwright
• Rosalind Eleazar as Louisa Guy
• Christopher Chung as Roddy Ho
• Aimee-Ffion Edwards as Shirley Dander
• Kadiff Kirwan as Marcus Longridge
• Jonathan Pryce as David Cartwright
• Hugo Weaving as Frank Harkness
• Joanna Scanlan as Moira Tregorian
• Ruth Bradley as Emma Flyte
• Tom Brooke as J.K. Coe
• James Callis as Claude Whelan

---

Where to watch Slow Horses season 4

Slow Horses season 4 will be available to stream exclusively on Apple TV+. The streamer is the only one to hold exclusive rights over the series for the global audience and includes all three previous installments. For those who are new to the series and the platform, the subscription plans of Apple TV+ range from $9.99/month to $99/year.

---

Plot summary

Below is the official logline of Slow Horses that describes the plot:

"Following a dysfunctional team of MI5 agents -- and their obnoxious boss, the notorious Jackson Lamb -- as they navigate the espionage world's smoke and mirrors to defend England from sinister forces."

---

Stay tuned for more news and updates on Slow Horses season 4 and all your favorite TV shows and movies as 2024 progresses.