Slow Horses Season 6 Episode 5 arrives Wednesday, October 14, 2026, on Apple TV. The episode, titled “Sayonara,” sends River after Sid, puts Jackson Lamb on Cantor’s trail and keeps Diana Taverner inside the dangerous deal driving the season.
Those confirmed story points show that the hit squad chase in “Lost and Found” does not settle the case. Instead, the pursuit separates the immediate survival problem from the conspiracy behind it. River focuses on Sid, Lamb follows the money and authority around Cantor, and Taverner continues making choices that may endanger everyone.
- Release date: October 14, 2026
- Episode: Season 6, Episode 5
- Title: “Sayonara”
- Genre: Spy thriller
- Streaming on: Apple TV
River goes after Sid
The published Episode 5 description says River pursues Sid. That wording is deliberately more troubling than a simple reunion. Sid’s return has already forced River to question where she has been since Season 1 and whether she is acting freely. After they run from the hit squad, he appears unwilling to let her disappear with those questions unanswered.
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River’s decision may also create a tactical mistake. The season’s killers have been exploiting the connections between current and former Slow Horses. Following Sid could lead River toward the truth, but it could also make both of them easier to track.
Lamb turns his attention to Cantor
Lamb sets his sights on Cantor after spending Episode 4 trying to determine who Frank Harkness serves. That does not confirm Cantor as Frank’s client. It does establish him as the next person Lamb believes can move the investigation forward.
Lamb’s method is usually to apply pressure where official MI5 cannot. Cantor may possess information about the operation, its financing or the list that exposed former Slough House agents. Whatever the connection, Lamb clearly sees him as more useful than chasing another gunman.
Taverner’s deal remains the largest risk
The preview also says Taverner continues a treacherous deal. Season 6 has made her secrecy part of the danger, not merely a bureaucratic obstacle. If she is bargaining to contain an earlier operation, every new concession could give the other side more leverage.
Frank Harkness remains another unresolved piece. Episode 4 links Lamb’s search for Frank’s employer to the flight of Sid, River and Coe, but the published Episode 5 synopsis does not say Frank has been captured or exposed. His absence from the preview should not be mistaken for resolution, safety or proof that he has left London. Episode 5 is the penultimate chapter, with the finale following on October 21. “Sayonara” therefore needs to expose enough of the conspiracy to set the final confrontation in motion. Will River find Sid before Lamb reaches Cantor? Share your prediction in the comments.
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