Jackson Lamb is still wearing that same disgusting trench coat. It probably smells like cigarettes and failure. Honestly, that’s exactly why we love this show. Following the explosive start to the year, Slow Horses season 4 episode 2 recap territory gets remarkably murky, shifting from the literal blast at Westacres to a more psychological, cat-and-mouse game involving families—both the ones you're born with and the ones you're stuck with at Slough House.
River Cartwright is in a bad way. Well, technically, David Cartwright thinks he’s in a bad way.
The episode, titled "A Stranger Comes to Town," picks up the pieces of that cliffhanger where we saw a body that looked suspiciously like River. But if you’ve watched more than five minutes of this show, you knew Jack Lowden wasn't exiting the series that early. It’s the how and the why that makes this hour of television so stressful.
The Identity Crisis in Slow Horses Season 4 Episode 2 Recap
The big reveal early on is that the man David Cartwright shot wasn't actually River. It was a decoy. An impostor. Someone who looked enough like the younger Cartwright to confuse a man sliding into the fog of dementia. This sets the stage for a frantic cover-up.
Lamb, being the cynical genius he is, arrives at the scene and immediately starts calculating the fallout. He sees the body. He sees David’s confusion. He knows that if the Park finds out the "O.B." (Old Bastard) has started executing intruders, David is going to be locked away in a facility faster than Lamb can finish a gin and tonic.
So, what does he do? He treats it like a Tuesday.
Lamb tells David to go upstairs. He starts cleaning. He treats a grizzly crime scene with the same level of interest most people give to a spilled bowl of cereal. It's a masterclass in Gary Oldman’s ability to be simultaneously the most repulsive and most competent person in the room. He’s protecting River by proxy, even if he’d never admit it.
Why the Body at the O.B.'s House Matters
The dead guy has a name: Adam Lockhead. Or at least, he has a passport with that name. River, who is very much alive and hiding in the shadows, realizes he’s being hunted by people who aren't just random thugs. These are professionals. The guy David killed was part of a hit squad, and he was specifically styled to look like River.
That is a terrifying level of planning. It suggests that whoever is behind the Westacres bombing has a direct, personal vendetta against the Cartwright lineage.
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River decides to go rogue. Again. Because he’s River.
Instead of checking in with the Park or Slough House, he takes the dead man’s identity and heads to France. It’s a bold move. It’s also incredibly stupid, which is very on-brand for him. He ends up in a tiny French village called Lavande, looking for the origins of the man who tried to replace him.
The New Boss and the Old Problems
While River is playing spy in France, the rest of the crew is dealing with Claude Whelan.
James Callis plays Whelan with this wonderful, shaky-handed insecurity. He’s the new First Desk, and he is clearly out of his depth. He’s trying to implement "transparency" in an organization that thrives on shadows. It’s like trying to run a vegan bakery in the middle of a wolf den.
Diana Taverner is just... waiting. She’s watching him fail. Kristin Scott Thomas is a treasure here, using nothing but a raised eyebrow to communicate that she could run circles around Whelan while sleepwalking. The tension in the Park is high because the Westacres bombing has everyone looking for a scapegoat.
- Whelan wants a clean win.
- Diana wants her old power back.
- The Dogs just want someone to tackle.
Emma Flyte, the new head of the Dogs, is the one to watch. She’s sharp. She’s not like the previous goons we’ve seen. She catches on quickly that Lamb is lying about... well, everything.
The Slough House Dynamic Shift
Back at the "garbage bin" of MI5, the slow horses are doing what they do best: bickering.
Catherine Standish is gone, and her absence is felt in every dusty corner. Ho is being an insufferable jerk about his "girlfriend" again. Marcus and Shirley are struggling with their own demons—gambling and drugs, respectively. It’s bleak.
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But when Lamb tells them that River is "dead," the reaction isn't what you'd expect. There’s a stunned silence, then a slow realization that the world just got a lot colder. Of course, Lamb knows River is alive. He’s just using the "death" as cover to keep the Park off their trail while River investigates the French connection.
The Mystery of Frank Harkness
We need to talk about Hugo Weaving.
He plays Frank Harkness, and he is chilling. We see him briefly, but his presence looms over the entire episode. He’s the one pulling the strings. He’s the one who sent the "twins" to kill the Cartwrights. There is a clinical, cold-blooded nature to his operations that makes the usual MI5 villains look like amateurs.
Harkness represents a new kind of threat for the series. This isn't just a political cover-up or a rogue agent. This feels like a private mercenary group with deep pockets and a specific interest in the history of British Intelligence.
The connection between Harkness and the Westacres bomber, Robert Winters, becomes clearer. These aren't lone wolves. They are part of a pack. A pack that was raised or trained for a specific purpose.
River’s French Adventure
The final act of the episode sees River in France, and the tone shifts into something out of a classic noir. The village of Lavande is beautiful but hostile. River is trying to find a house that appears in a photograph he found on the dead man.
He finds it. But he also finds a group of locals who are not happy to see him.
The episode ends with River being held at gunpoint. It’s a classic cliffhanger, but it feels earned. We’ve moved from the foggy streets of London to the sun-drenched, dangerous countryside of France. The stakes have never felt more personal.
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Key Details You Might Have Missed
The show is famous for its "blink and you'll miss it" clues. In this Slow Horses season 4 episode 2 recap, pay attention to the way David Cartwright reacts to the word "Les Arbres." It clearly triggers something in his memory, something from his days as a high-level spook in the Cold War.
Then there’s the badge. The "Brotherhood" or whatever this group calls themselves. It’s a small, subtle detail on the clothing of the operatives. It suggests a cult-like loyalty.
Also, Lamb’s interaction with the funeral director. It’s dark comedy at its best, but it also shows how far Lamb is willing to go to protect his people. He’s willing to fake a death, forge documents, and lie to the face of the First Desk just to give River a few days of head start.
Final Thoughts on the Episode's Impact
This isn't a show about heroes. It’s a show about broken people who are occasionally less broken than the villains they fight.
The pacing in episode 2 is much faster than the premiere. We’ve established the threat, and now we’re seeing the response. The contrast between the high-tech surveillance of the Park and the "old school" legwork of River in France highlights the theme of the season: the past always comes back to haunt you.
David Cartwright is the key. His declining mind holds the secrets to a conspiracy that started decades ago. The tragedy is that he might forget the truth before River can find it.
Actionable Insights for Fans
If you're trying to keep up with the dense plotting of Mick Herron's world, here are a few things to keep in mind moving forward:
- Watch the O.B. closely. David Cartwright’s "ramblings" are rarely just ramblings. Every name he mentions is likely a real figure from his past.
- Follow the money. The Westacres bombing was expensive. A private militia like the one Harkness runs requires massive funding. Look for a corporate or state-sponsored link.
- Don't trust the Park. Whelan is a puppet. Taverner is the puppeteer. If someone at the Park says something, assume the opposite is true.
- Keep an eye on the Slough House newcomers. Every time a new "horse" arrives, they bring baggage that eventually explodes.
The mystery of who Robert Winters really was—and why there are more like him—is only going to get darker. River is isolated in France, Lamb is juggling a dozen lies in London, and the "Stranger" has definitely come to town.
Next time you watch, pay attention to the background characters in the Park. The show loves to hide the real threats in plain sight, usually behind a desk or a computer screen. The game is afoot, and so far, the horses are running behind. Which is exactly where they want to be.