‘Slow Horses’ Season 5 Ending Explained – The More Things Change…

By Jonathon Wilson - October 29, 2025
Sir Gary Oldman and Jack Lowden in Slow Horses Season 5
Sir Gary Oldman and Jack Lowden in Slow Horses Season 5 | Image via Apple TV+
By Jonathon Wilson - October 29, 2025

WARNING: THIS ARTICLE CONTAINS MAJOR SPOILERS

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Summary

Slow Horses has a good track record of great finales, and Season 5’s is no different, delivering an exciting ending full of dramatic payoff, though admittedly little closure, as Slough House and its agents continue to thanklessly carry on.

And just like that — this show should have more than six episodes per season, shouldn’t it? — we’ve reached the end. Again. Slow Horses is consistently very good at finales, and Season 5’s is no different. The terrorists are foiled, the day is saved, and… very little changes, that being the way of the espionage game. It’s all in the fine details, who’s sitting behind which desk when the smoke clears. And in that regard, at least, “Scars” represents a pretty momentous shift for the series, in ways both obvious and not.

While the penultimate episode veered wildly away from the events of the source material, Mick Herron’s London Rules, Episode 6 brings us back in line, more or less, with its original conclusion. The broad strokes are the same, aside from a few characterful flourishes. It’s better in some ways, worse in others, which is pretty good going for a book adaptation, since they tend to be worse in every way. And it’s a climax full of fun implications for the already confirmed — and presumably already filmed, based on the teaser at the end — sixth season. Let’s unpack it.

The Ticking Clock

As if it wasn’t bad enough that the Park’s supposedly impregnable digital security has been bypassed, every screen in the building suddenly displays a countdown timer. A literal ticking clock. The boffins assure Whelan that something can be done to fix it, but not before the timer runs down, which means that whatever it’s counting down to is going to happen. Unless…

Just like that, the Libyan ambassador is on the phone, full of apologies for the dissident group responsible for the recent atrocities. Part of why he’s feeling so sorry is that Tara is holding him at gunpoint. She has some demands: £100 million as recompense for lost oil revenue — a small fraction, she claims, of what is really owed — and free passage out of the country, or they’ll attack a place of worship. This being Sunday morning, that’s a potential target list roughly 5000 strong.

Whelan is way out of his depth, obviously. In between advising the tech experts to turn the entire MI5 database off and on again, asking for clarification from a Sikh about whether Muslims worship on Sunday, and refusing to even entertain the idea of paying the terrorists off with money that, in a roundabout sense, they’re probably due on some level, Tara gives him the ultimate insult — she’ll only speak to Diana Taverner.

Lamb Is A Step Ahead

The terrorists want the money paid into a Cayman Island Trust tied to a company that Peter Judd is a director of, which explains his visit to Lady Di earlier in the season. As it turns out, he has been taking a “nominal fee” from the Middle East over the last three years for services rendered — services that Judd promptly forgot to render, presumably at the same time he forgot to declare the payments to HMRC. It’s a scandal waiting to happen. The U.K. has been profoundly outmaneuvered.

So, Lady Di calls Tara back and pays up. The Dogs will even escort her and the other terrorists to the airport, supposing they surrender — which, obviously, they don’t. Tara thinks the point has been proven, but her more militant colleagues think differently and plan to go through with the rest of the destabilization strategy regardless. That leaves Tara stranded in the Libyan Embassy with the Dogs ready to storm the place. Who else to the rescue but Jackson Lamb and Catherine Standish?

Lamb has already figured all this out, obviously. He has a good read on the “place of worship” — a multifaith commemoration of the Abbotsfield disaster attended by Zafar Jaffrey — and has intuited that Tara will have been abandoned in the embassy. While he eats a sausage roll, he sends Catherine to knock on the door. Tara brings her out as a hostage and tries to make her escape, but Lamb cuts her off and holds her up so the Dogs can arrest her.

Kristin Scott Thomas in Slow Horses Season 5

Kristin Scott Thomas in Slow Horses Season 5 | Image via Apple TV+

Slow Horses to the Rescue

While the Slow Horses are on a roll, River, Shirley, and JK Coe descend on the commemorations in Abbotsfield to interrupt Jaffrey’s bad-taste quoting of Dominic Toretto and evacuate the building. They’d have probably saved everyone if it weren’t for Jaffrey’s delusional arrogance causing him to call Whelan personally before he agrees to leave. Whelan isn’t a good conversationalist. By the time he has finished stammering through excuses for why the Mayor of London wasn’t kept in the loop about a possible attempt on his life, Farouk and Kamal have opened fire with automatic weapons.

River — in a tracksuit! — and Shirley fire back, taking down Kamal, but Farouk gets a hold of Jaffrey as a human shield. Luckily, the slow horses are so fundamentally inept that their bickering back and forth provides enough of a distraction for Coe to sneak up behind Farouk and stab him to death. All part of the plan!

With the day having been presumably saved, River even finds time the next day to visit his grandfather, who was calling him incessantly the night before. As was made obvious by his muddled reiteration of why bees are important, he clearly recognises the steps of the destabilisation strategy from his days in the service. River is barely listening, again. But something he says resonates. It was always part of the plan to attack again once the enemy thought the attacks were over. The sting in the tail, so to speak. Like the bees.

The More Things Change…

River — still in a tracksuit! — calls Lamb to tell him that one of the terrorists remains at large. Indeed, earlier we saw Sami break off from the others. Lamb tips River off that Whelan is the target, since the file that was stolen from the MI5 database pertained to him. And, as usual, he’s right. Sami ambushes Whelan on a run and holds him at gunpoint. He’s guilty of the crime of condemning Libya to its fate. When he was a long-term political forecaster, he had deemed Libya unworthy of investment since it had no bearing on British security. That forecast became policy. To Sami, he’s personally responsible for every hardship he has experienced.

River arrives just in time to save Whelan and kill Sami, which, when he meets with Lamb the next day, he thinks will secure him a promotion all the way back to the Park. He even calls Louisa to tell her so. But, as ever, he’s misguided. When Lamb gets to his office, Whelan is waiting for him. He has privately made a deal with Judd to pin the blame for all of the recent events on Slough House. That way, Judd gets to keep his commission on the £100 million ransom, and Whelan gets to keep his job. Slough House is closing its doors.

Only, not quite. Lamb is in possession of the recording of Whelan threatening Dennis and Dodie Gimball. It’ll do as leverage. Not only will Slough House remain operational, but Lamb will be left alone, Molly and Roddy will get their jobs back, and Whelan will resign. If not, his reputation will be ruined, and irreparable damage will be done to the Service. Whelan has no choice. Lady Di becomes First Desk, though she’s adamant that she will not be hiring River Cartwright. Hopefully, Jackson will find a use for him.

The ending of Slow Horses Season 5 is, unusually, focused on the bottom of Jackson Lamb’s feet. They’re a mess. I’m sure you recall the story he told in Episode 3, which he claimed definitely wasn’t about him, about the British spy who was captured by the Stasi and tortured in front of his pregnant lover by having the soles of his feet repeatedly burned.

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