Slow Horses Season 1 review – Failure as a superpower

🐴 Introduction

🐴 This review is part of our Slow Horses hub — every season reviewed and ranked, plus why the show works so well and what is coming in Season 6.

There is a moment about twenty minutes into the first episode where you understand exactly what kind of show this is going to be. Jackson Lamb, played by Gary Oldman, is asleep at his desk in a building that appears to be held together by damp and takeaway containers. A junior agent needs something from him. Lamb does not open his eyes. He simply breaks wind, and continues sleeping.

That is the thesis. Slow Horses is a spy show about the people the intelligence service could not quite bring itself to fire. They messed up. They drank, they gambled, they lost a disk on a train, they failed a training exercise in front of the wrong person. So they got sent to Slough House, a dead-end annexe where the work is deliberately pointless and the hope is that boredom will do what human resources could not.

For a dad who grew up on Tom Clancy paperbacks, this is a slightly disorienting proposition. Clancy’s world runs on competence. Jack Ryan is smarter than the room and the machine mostly works. Mick Herron’s world runs on the opposite assumption: the machine is staffed by people, people are venal and tired and covering their own backs, and the only reason anything gets solved is that a handful of humiliated failures have nothing left to lose. It turns out that is a far better engine for a thriller.

🧠 Story & themes

The plot is a proper one. A young man named Hassan Ahmed, played by Antonio Aakeel, is snatched off a Leeds street by a group calling themselves the Sons of Albion, who announce they will behead him on a livestream in less than two days. It is an ugly, credible premise, and the show refuses to make it comfortable. Hassan is not a plot device in a basement; we sit with him, we watch him try to talk his way out, we watch him fail.

Meanwhile River Cartwright, played by Jack Lowden, is stuck in Slough House after blowing a training exercise at King’s Cross in the opening minutes of the series. He is the grandson of a legendary spymaster, David Cartwright, played by Jonathan Pryce, which means his exile carries a particular sting: he was supposed to be somebody. When the kidnapping turns out to have threads leading back inside the service, River does what River always does. He goes off on his own, without permission, and makes everything considerably worse before he makes it better.

The theme running under all of it is institutional self-preservation. Kristin Scott Thomas plays Diana Taverner, Second Desk at MI5, with a chilly, beautifully judged pragmatism. She is not a villain. She is a senior manager protecting a career, which is far more frightening, because you have met her. Everyone who has worked in a large organisation has met her.

And that is where the show quietly gets its hooks into a working parent. The Slow Horses are not failures because they are stupid. They are failures because one bad afternoon got written into a file, and the file followed them, and now they do the work nobody reads. The fantasy on offer here is not that you get to be Bond. It is that the thing you got wrong once does not have to be the last word.

🎭 Characters & performances

Gary Oldman is the reason this show became what it became. Lamb is repellent by design: he stinks, he smokes indoors, he says the cruellest available thing to the person least able to take it. Oldman plays him without a single bid for sympathy, and it works because underneath the squalor there is a man with an intelligence-service brain that never switched off and a loyalty to his people that he would rather die than admit to. The comedy and the menace come from the same place, and Oldman never signals which one you are about to get.

Jack Lowden has the harder job. River could easily be an irritating posh boy with a grievance, and in the first two episodes he nearly is. Lowden plays the wounded ambition straight, which lets the character earn his good moments rather than being handed them.

The supporting bench is where the show gets its depth:

• Saskia Reeves as Catherine Standish — the recovering alcoholic who runs the office and knows precisely what Lamb is. Their scenes together are the emotional spine of the whole series.
• Olivia Cooke as Sid Baker — sharp, capable, and clearly at Slough House for reasons that do not match anybody else’s. Cooke only appears in three episodes and still leaves a hole.
• Christopher Chung as Roddy Ho — the hacker with a self-image roughly nine thousand percent larger than his social skills. A running joke that never quite tips into cruelty.
• Rosalind Eleazar and Dustin Demri-Burns as Louisa Guy and Min Harper — two people rediscovering that they are good at something. Demri-Burns in particular makes Min’s ordinariness genuinely likeable.
• Freddie Fox as Spider Webb — the smug one who got the career River wanted. Perfectly hateable.

🎬 Craft: Six episodes, no fat

James Hawes directed all six episodes, and Will Smith adapted the novel, and between them they made the single most valuable decision in modern television: they stopped when the story stopped. Six episodes. Roughly 45 minutes each. No mid-season detour into a character’s backstory, no episode that exists because a streaming contract said eight.

The look supports it. London here is grey, wet and administrative — bus shelters, dual carriageways, strip-lit offices, the back of a service station. When the show does go to the glass-and-steel version of MI5 at Regent’s Park, the contrast does the work that dialogue would otherwise have to do. Slough House itself is a masterpiece of set design. You can smell it.

Then there is the title sequence. Mick Jagger co-wrote and performs Strange Game with composer Daniel Pemberton, and it is one of the great modern TV themes: sardonic, a bit sleazy, unmistakably about people who have been discarded. Jagger had read the novels before writing it, which explains why it fits so precisely. Do not skip the intro. Nobody skips the intro.

👨‍👧 The dad perspective

The practical case for this show is strong. Six episodes at 45 minutes is about four and a half hours total, which is one weekend of stolen evenings. There is no homework, no wiki, no seventeen-character politics chart. The plot resolves. Things happen and then they matter.

What makes it a genuinely good use of limited evening time, though, is the density. Herron’s dialogue survives the adaptation intact, which means a scene will hand you a laugh, a piece of plot and a character revelation inside the same forty seconds. Very few shows respect your attention that much.

Age guidance: we would say 15 and up, and honestly we would keep it to adults. The language is relentless. The violence, when it lands, is sudden and unglamorous rather than choreographed. And the kidnapping thread is meant to be upsetting, which it is.

Rewatch value: high, and it improves. Once you know where the season is going, Lamb’s throwaway lines in the first two episodes reveal themselves as him being about four steps ahead the entire time. If you watch it on an Apple TV 4K, the grade holds up well on a decent panel — this is a show shot in a lot of low light, and cheap streaming compression is not kind to it.

✅ Pros & cons

Watching on a different setup tonight? Prime Video’s 30-day free trial is a reasonable way to fill an evening while you decide, though catalogues shift constantly, so check what is actually on it before you commit.

Is Slow Horses Season 1 worth watching?

Absolutely. It is a 5 out of 5 for us. Six episodes of roughly 45 minutes each, no filler, a proper thriller plot and a career-highlight performance from Gary Oldman. If you have ever bounced off a glossy spy show because nothing was at stake, start here.

Do I need to read the Mick Herron books first?

No. Season 1 adapts the first novel closely enough that the show stands entirely on its own. The books are a genuine pleasure afterwards, and reading them in publication order matches the season order almost exactly.

How many episodes are in Slow Horses Season 1?

Six episodes, released weekly on Apple TV from 1 April to 29 April 2022. Each one runs around 45 minutes, which makes a season roughly the length of two films.

Is Slow Horses suitable for kids?

No. We would put it at 15 and up. The language is constant and creative, the violence arrives without warning, and the central kidnapping thread is genuinely distressing. This is a show for after bedtime.

Who sings the Slow Horses theme song?

Mick Jagger performs the title track, Strange Game, which he co-wrote with the show’s composer Daniel Pemberton. Jagger had read the novels before writing it, and the song fits the show’s shabby, off-kilter tone perfectly.