James Oconner 
Anil Krishna 
Jonathan Millar 
“Sayonara” and Sacrifice: Breaking Down Slow Horses Season 6, Episode 5
© Apple TV+
Major spoilers ahead for Season 6, Episode 5 of Apple TV+’s Slow Horses.
With just one episode left, Slow Horses is wasting no time raising the stakes. Episode 5, “Sayonara,” picks up right where last week’s cliffhanger left off, and things get ugly pretty quickly. Sid Baker is in serious trouble after being abducted by GRU assassins, while Diana Taverner is doing everything she can to keep her own mess from blowing up in her face. The problem is that, as usual, the people at the top seem perfectly willing to let someone else pay the price for their decisions.
There’s a lot going on here, from Sid’s desperate escape to River making a choice that could cost him everything. And just when it looks like the season’s various conspiracies are finally starting to make sense, the episode throws in another betrayal. Here’s what happened in “Sayonara” and what it could mean for the finale.
1. Sid Finds a Way Out, but the Danger Isn’t Over
Last week ended with Sid being bundled into a car by GRU assassins Jim and Jane, shortly after JK Coe’s brutal murder. It looked like she was being taken away to meet the same fate, but Sid isn’t someone who gives up without a fight. She uses a souvenir license plate marked “RIVER” to slash Jane across the face, causing the speeding car to crash. It’s a desperate move, but it gives Sid the opening she needs.
Jane’s body disappears from the wreckage, which is a pretty worrying detail considering how dangerous she is. Sid, meanwhile, manages to escape into the nearby forest, although she doesn’t get very far before Jim catches up with her by a lake. He tries to drown her, and for a moment, it looks as if she’s finally run out of luck. River arrives just in time, though, and gets dragged into a vicious fight with Jim. With Jim wielding a knife, Sid grabs a rock and strikes him, giving them the chance to turn the tables. She and River eventually drown him, putting an end to the immediate threat. What makes the scene work is that Sid isn’t simply waiting around for River to save her. She fights back, makes her own decisions, and plays a major part in getting them both out alive.
2. Diana Taverner Has a Lot More to Hide Than She Admits
Diana’s problems come to a head when she’s questioned by the Limitations and Oversight Committee. Under pressure, she admits to arranging an unauthorized assassination of a GRU operative in Kazan, supposedly as payback for earlier Russian nerve gas attacks on British soil. That alone is enough to cause a serious scandal, but the money behind the operation turns out to be an even bigger problem.
Diana used funds seized from Peter Judd to pay for the hit, even though the money actually belonged to media mogul Damien Cantor. Cantor has his own reasons for keeping the Russians happy, particularly because he’s trying to secure a major media distribution deal in Russia. He’s also tied to GRU chief Vassily Raskanov, which means Diana’s secret operation has become part of a much larger political and financial mess.
And Diana’s solution? She decides Sid is expendable. Years earlier, Diana had faked Sid’s death and hidden her under another identity. When she brought that identity back into play for the Kazan operation, she effectively put Sid in the firing line. Now that Raskanov wants blood and Diana needs to protect herself, Sid becomes the easiest person to sacrifice. The betrayal gets even worse when MI5 appears to rescue River and Sid from the woods. They’re actually being taken to a private airfield, where the plan is to hand them over to the GRU as part of a supposed neutral-territory transfer to Bulgaria. So much for MI5 looking after its own.
3. River and Sid Finally Stop Pretending
The relationship between River and Sid has been simmering in the background, and Episode 5 finally gives viewers a moment they’ve been waiting for. The timing couldn’t be much worse, of course. Once they realize the airfield transfer is really a setup to deliver Sid to the Russians, they know they’re running out of options. With the possibility of never seeing each other again hanging over them, they finally admit how they feel and share a passionate kiss.
But River doesn’t stop there. He refuses to let Sid be handed over, so he steals an airfield maintenance vehicle and helps her escape toward the surrounding wilderness. It’s a risky move, and neither of them can realistically expect to outrun MI5 forever. River seems to understand that, which is why he makes a difficult choice: he sends Sid on alone and returns to the base to surrender himself. It’s a way of drawing attention away from her and giving her a chance to disappear before anyone can catch up. Whether this sacrifice will actually protect Sid remains to be seen, but River has made his priorities pretty clear. For once, his feelings aren’t something he’s willing to bury beneath another sarcastic remark.
4. Jackson Lamb Starts Connecting the Dots
While River and Sid are trying to stay alive, Jackson Lamb is working on the other side of the conspiracy. His investigation into the money and the people benefiting from it leads him toward Damien Cantor and, eventually, Natasha Carrington, who appears to be helping Cantor with his Russian media ambitions.
Lamb tries to follow Natasha, but she manages to lose him without much trouble. That might seem like a small moment, but it tells him quite a bit. Natasha doesn’t behave like an ordinary business intermediary. She’s far too good at avoiding surveillance, suggesting she has intelligence training of her own and may be playing a much bigger game than Cantor realizes. As Cantor becomes less useful to the Russians, the people around him could find themselves in trouble, too. Lamb hasn’t uncovered the entire picture yet, but he’s getting closer, and it’s hard to imagine him leaving this alone once he understands just how badly MI5 has compromised itself.
What to Expect in the Slow Horses Season 6 Finale
The finale has plenty to sort out, and River and Sid’s situation is only part of it. Diana’s decision to sacrifice one of her own agents could have consequences well beyond the immediate scandal, especially if Lamb manages to expose the people behind the handover.
- Can River get out of this alive? River has openly defied Diana and interfered with an operation involving the GRU. He’s put himself in a dangerous position, and even if MI5 doesn’t treat him as a traitor outright, there will be people eager to make an example of him. Lamb may be his best hope, assuming he can find a way to help without making the situation even worse.
- What happened to Jane? Her disappearance after the crash is hard to ignore. If she’s still alive, she could come after Sid again, and she certainly isn’t the kind of person who’ll quietly disappear into the background.
- Can Sid actually get away? River has bought her some time, but she’s still being hunted, and the danger isn’t coming from the Russians alone. Her own agency has effectively marked her for death, which makes escaping a lot more complicated than simply getting out of the forest.
With one episode remaining, “Sayonara” leaves the season in a pretty grim place. Diana is trying to save herself, River has put everything on the line for Sid, and Lamb is closing in on a conspiracy that reaches well beyond one botched assassination. The finale will have to bring these threads together, and Sid’s missing assassin could make an already messy situation even worse.
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