‘Slow Horses’ Season 5: Everything To Know So Far About The Grumpiest Spymaster And His Stable’s Return (May 2025 Update)

How long can Slow Horses keep riding on Apple TV+? Author Mick Herron has amassed eight full-length Slough House books (and a ninth on the way), so the Gary Oldman-starring spy series could easily keep going for many more years. Currently, the show also qualifies not only as one of the most best spy series on TV (alongside the likes of Black Doves) but also one of the most popular (within the ranks of The Night Agent).

Slow Horses, however, is a truly unique beast in the streaming world. Not only does the show manage a relative breakneck pace (after surfacing in 2022, the upcoming season has been done and dusted for months), but this show has the devil in it (both from the brilliant spymaster and those surround him), so let’s not waste any more time and talk about the fart-cloaked season to come.

Plot

This season will adapt Herron’s London Rules novel, and first, it’s important to note that Gary Oldman stressed to Radio Times that Apple has been wonderful about “writing the cheques” for this series, and although Netflix will swiftly cancel shows, “Apple will not do that. We’re working on writing number six. Now, I don’t know whether we’ll eventually end up doing it, but we’ve filmed five and there’s eight books altogether.” Also, Herron wrote a ninth book, Clown Town, that is due out in September, so fingers are crossed that these spies-in-purgatory can continue after the sixth season, which will adapt both the Joe Country and Slough House.

Oldman has teased that the fifth season will contain tidbits about Jackson Lamb’s previous spy adventures, and of course, there will be food-related shenanigans to keep the spy-thriller vibes from overriding the sheer pleasure of witnessing the characters. This silliness will, according to showrunner Will Smith, include Jackson Lamb eating “too much cake” that will prompt “a sugar rush,” and this cannot be great for his digestive tract. And I cannot wait.

Meanwhile, hints have dropped from Christopher Chung (who portrays Roddy Ho). He recently told Radio Times that his insufferable techie character (and this question has been asked on social media) will keep evolving, and in the fifth season, “[H]e becomes a little bit louder and a little bit more self-assured, even more so than he already is, but I think you’ll be in for a bit of a surprise.” This will add up to Roddy having a larger role, and “because London Rules has such a heavy focus on Roddy, I was hoping we would get to season 5.” Also according to Chung, the new Roddy happenings include a “glamorous new girlfriend” that nobody at Slough House trusts.

Now onto the actual plot details, which will include how the fourth season finale suggested that River Cartwright’s (Jack Lowden) allegiance has become clear due to that pub visit with Jackson. Despite a mercenary job offer from his dad, Frank Harkness (Hugo Weaving), River should still be hanging with the Slough Horses. The London Rules novel synopsis, however, highlights the mayhem and trauma to come:

At MI5 headquarters Regent’s Park, First Desk Claude Whelan is learning the ropes the hard way…. Meanwhile, the country’s being rocked by an apparently random string of terror attacks.

Over at Slough House, the MI5 satellite office for outcast and demoted spies, the agents are struggling with personal problems: repressed grief, various addictions, retail paralysis, and the nagging suspicion that their newest colleague is a psychopath. Plus someone is trying to kill Roddy Ho. But collectively, they’re about to rediscover their greatest strength—that of making a bad situation much, much worse.

Cast

Gary Oldman wants to portray Jackson Lamb until acting retirement, and nobody is arguing with him. Additionally, Jack Lowden ^^^ will be back as River Cartwright with Christopher Chung as Roddy Ho. Other returning cast members include Kristin Scott Thomas as Diana Taverner, Rosalind Eleazar as Louisa Guy, and James Callis as Claude Whelan.

Release Date

Even though Apple TV+ has been hanging tight on a precise release date, Slow Horses is guaranteed for a 2025 return. This will probably happen no later than August 2025 since the previous seasons landed less than a year apart (with the last one in September 2024). Take that, Severance.

Trailer

Although we’re not lucky enough to have seen footage or a trailer yet, Gary Oldman talking about how James Bond won’t fart never goes out of style.