Six seasons in, it’s ridiculous to even refer to Apple TV’s Slow Horses as underrated. Yet it very much is, feeling like the best-kept secret on TV. It’s different from other spy series out there, abandoning the concept of near-superhuman agents to showcase the heavily flawed but resilient people of Slough House. It’s sharp, believable, and brilliant – but why aren’t more people screaming about it from the rooftops?
In Slow Horses Season 6, the stakes are even higher. Diana Taverner (played by Kristin Scott Thomas) is now First Desk at MI5, while ghosts from the past return and former members of Slough House turn up dead. The trailer has already ruined a few surprise returns, but don’t let that deter you here. It’s arguably the most thrilling instalment of the show yet.
Like before, this season is only six episodes long, but it doesn’t waste time on trivial matters and side quests. The action and suspense unravel at a pace that should become the gold standard for every TV show. Despite the “slow” in its title, Slow Horses never moves in slow motion nor occupies time to put out another episode for the sake of it. The pace grips and teases the audience to hang on tight for what’s around the corner. Honestly, this isn’t rocket science; it’s simply good storytelling.
The biggest compliment that can be paid is that there has been a switch in showrunner from Will Smith to Gaby Chiappe, and the changeover isn’t noticeable. It still looks, feels, and flows like the same series, and Chiappe took the right approach in leaving well enough alone. Why fix something that isn’t broken, right?

What elevates Slow Horses Season 6 beyond what came before, though, is the emotional stakes and outcome of the story. This show hasn’t been afraid of breaking the viewer’s heart in the past, and this season does it on more than one occasion. By the end, you know that things will never be the same again for Jackson Lamb and his Joes.
Speaking of Lamb, Gary Oldman continues to steal every scene as the foul but loyal leader of Slough House. This season, the threats come from all angles – and trust becomes a bigger issue as his relationship with Taverner takes an unexpected turn – so Lamb needs to put his trust in his team more than ever.
Jack Lowden’s River Cartwright steps up as always. River might not be a carbon copy version of James Bond, but he demonstrates enough charisma and recklessness that make you understand why Lowden is one of the rumored frontrunners for the role. His character’s personal turmoil adds another complicated layer to the proceedings, as viewers wonder if River will ever find his spark of happiness again.

Christopher Chung’s Roddy Ho remains the comedic relief of the series. Having said that, his character arc continues to evolve beyond antagonistic and narcissistic internet troll to somebody whom you underestimate at your own peril. Everybody should be paying closer attention to Chung as an actor, because he should be leading his own films and shows by now.
So, what else can be said about Slow Horses Season 6? Watch it. It’s one of the best spy series on TV – yes, better than The Night Agent and The Agency. This show deserves all the praise because it hasn’t dropped one single bad episode yet, and the same standard is upheld for the sensational sixth season.
RELATED: Apple TV’s Answer to James Bond Is One of the Highest-Rated Spy Shows on Rotten Tomatoes
Slow Horses Season 6 premieres September 16, 2026 on Apple TV.
Slow Horses |
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A dysfunctional team of MI5 agents navigate the espionage world's smoke and mirrors to defend the UK from sinister forces. |
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| Creator: Will Smith / Mick Herron |
| Cast: Gary Oldman, Jack Lowden, Kristin Scott Thomas, Jonathan Pryce, Hugo Weaving, Saskia Reeves, Rosalind Eleazar, Christopher Chung, Aimee-Ffion Edwards |
| Genre: |
| Number of Seasons: 6 |
| Streaming Service: Apple TV |
The Review
Slow Horses Season 6
Slow Horses continues to be the best spy series on TV.
Review Breakdown
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Verdict













