‘Slow Horses’ Season 6 Episode 4 Recap & Ending Explained: JK Coe’s Death and Sid’s Danger

Few spy dramas can make you laugh out loud and wince in the very same scene, but ‘Slow Horses‘ has always lived in that uncomfortable space. This week’s chapter pushed it further than usual, and it deserves a proper ‘Slow Horses’ recap and ending explained. If you haven’t watched “Lost and Found” yet, consider this your spoiler warning.

The Apple TV series is adapted from Mick Herron’s ‘Slough House’ novels, and the latest run draws on ‘Joe Country’ and ‘Slough House’. The season premiered on September 16, with new episodes arriving weekly through October 21. Comedian Lenny Rush also joined the cast this year.

The premise this time is brutally simple: the exiled spies of Slough House are being hunted. Gary Oldman, who plays Jackson Lamb, told TV Insider he found the story interesting because “the horses were being targeted.” This episode shows exactly how high the cost of that hunt can climb.

The episode picks up with River (Jack Lowden), Sid (Olivia Cooke) and Coe (Tom Brooke) looking for a phone so Sid can call Diana Taverner (Kristin Scott Thomas). River hates the idea, and he is not shy about saying so. Having escaped the bowling alley, the trio eventually reach a shopping center, hoping the crowds will offer some cover.

It doesn’t last. The two assassins, Jim and Jane, track them down again, forcing the group to split up. The scene is tense, but it also sets up the episode’s real damage.

Coe is playing a racing sim in the arcade when he spots the killers and follows Jim into the men’s room. What follows is a strangely friendly exchange between two kindred spirits, with Coe quickly realizing that Jim is Russian military. Coe even tells him, “I think you’ve got the wrong list,” which hints that the Russians may have misunderstood who they are hunting.

The fight itself happens off-screen. Coe and Jim have a knife fight in the bathroom, and it leads to Coe’s death. River arrives too late and finds him lifeless against the wall.

Very much so. Outside, River spots Coe’s car pulling out in a hurry and realizes Sid has been taken. By the end of the episode Sid is captive of Jim and Jane, leaving River without backup, a vehicle, a phone or a gun.

The bigger problem is that Sid’s instinct to trust Diana may be the worst call of the episode. River warned her that she’d forgotten what the First Desk is capable of, and the plot proves him right.

The call Sid wanted to make is really about Vassily Rasnakov, Russia’s First Desk, who is furious about a hit on Russian soil and demands that Sid be handed over. Diana hypothetically agrees to sell her out in exchange for his assassins ceasing to target the other agents on his list. She does this without telling Lamb or anyone else in power.

Damien Cantor is circling the same situation, and a house call to Diana’s place suggests he is playing a bigger game. The picture that emerges is of a spymaster compromised from several directions at once. It also raises the question of whether the Slow Horses are being killed over a case of mistaken identity.

Not everyone will make it out of Slough House alive. #SlowHorses Season 6 premieres September 16. https://t.co/uznKQ0VSAE

— Apple TV (@AppleTV) August 18, 2026

Away from the carnage, the episode delivers some of its funniest moments. Lamb, Roddy Ho and Reece Nesmith turn up at the apartment of the recently sacked Emma Flyte, looking for help. A meeting is arranged with the number in Reece’s father’s burner phone.

At the meet, Lamb is unsurprised to see Frank Harkness across the table. Lamb creates a public disturbance that distracts Frank and his men, buying time to escape with Reece in Flyte’s car. They then tail Frank to a restaurant, where Flyte spots him sitting with Cantor, a clue Lamb will surely chase.

The closing moments leave the Slow Horses scattered and exposed. Coe is gone, Sid is in enemy hands, and Diana has made a deal that could cost her team dearly. One critic called it a tragic, hilarious, nail-biting episode, while noting that questions remain about whether Sid is telling the truth.

With only a couple of episodes left, River must now rescue someone who may or may not be hiding something.

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