‘Slow Horses’ Director Reveals a Happy Ending Was Filmed for River and Sid, but the Show Went Another Way

Few spy shows are as comfortable with misery as ‘Slow Horses.‘ Its heroes are MI5 rejects, its victories are rarely clean, and its most beloved characters can disappear in a sentence. Viewers have learned not to expect a happy ending, which made the sixth season finale’s final moments feel both brutal and strangely familiar.

Season 6 ended with a cliffhanger that left fans arguing about whether Jack Lowden’s River Cartwright is dead. The finale, titled ‘Judgment Day,’ aired on October 21 on Apple TV, and the show’s creators have been fielding questions ever since. Now the season’s director has offered a surprising answer about how close the story came to something much gentler.

The ‘Slow Horses’ director’s happy ending revelation comes from Adam Randall, who told Variety that “we had two endings, and one of them was happy.” He added that the alternative would have been a lovely, almost Spielbergian conclusion to River’s journey had it been the end of the series, but the book and the story planned for Season 7 demanded the other version.

The cliffhanger works because it begins as a fairy tale. After a brutal season, River deduces that Sid Baker, played by Olivia Cooke, is waiting for him at his late grandfather’s house, and the two appear poised for the night together that fans have waited for. Instead, the scene turns sinister, leaving River unconscious just when he believes the worst is behind him.

Reports describe River as poisoned, with the earlier presence of a character named Jim in the house offering the clue. His death hasn’t been confirmed, and one outlet notes his condition could point to a Russian trap. Head writer Gaby Chiappe has said she expects audiences to rewatch the episode to check what they saw.

The twist hits harder because Sid’s return was a big part of the season. She was presumed dead after the first season, although fans of the books had long expected her to come back. The blossoming romance between her and River gave viewers something rare in this world: a sliver of hope.

Randall acknowledged how difficult it was to keep her return secret. He said he was amazed no one spotted Cooke while Season 6 was shooting, but the next season’s shoot is much more public. With production moving out into London, he suggested it won’t be easy to hide Lowden’s presence, which makes any attempt to keep River’s fate secret a challenge.

The finale capped a bruising season for Slough House. The team lost Coe, played by Tom Brooke, and honorary Slow Horse Emma Flyte, played by Ruth Bradley, and several of their enemies met sticky ends as well. Gary Oldman’s Jackson Lamb and Kristin Scott Thomas’ Diana Taverner finally teamed up against a common enemy, and Hugo Weaving’s Frank Harkness escaped.

Randall also explained the thinking behind Coe’s death, saying he considered intercutting the fight with River slowly eating a sandwich because it felt like a very ‘Slow Horses’ way of doing it. Brooke was reportedly emotional watching the result and was happy with it.

Fans have also debated a moment in the church, where the surviving Slow Horses raise a drink to Coe, but not to Flyte or their other fallen colleagues. Randall said the scene was never about naming specific people, and that Lamb has simply experienced more loss than the rest of them. It’s a small beat, but it captures the show’s quiet understanding of grief.

He also pointed out that the books establish new Slow Horses, a hint that the team will keep evolving. The comment suggests the show’s future will involve change as well as continuity.

Here’s the first teaser for #SlowHorses Season 7! Releasing next year on Apple TV https://t.co/LaTlq2TUPs

— Apple TV News Hub (@AppleTVNewsHub) October 21, 2026

Apple TV has already renewed the series for a seventh season of 6 episodes, with Robert McKillop directing and Ben Vanstone as showrunner. A teaser followed the finale, and the new episodes are expected to arrive next year, though no date has been announced. Randall is also set to return for Season 8.

Some commentators have tied River’s uncertain fate to rumors that Lowden could be the next James Bond, but nothing about that has been confirmed. For now, the cliffhanger remains exactly that, and ‘Slow Horses’ fans have a long wait.

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