Slow Horses season 6 features one of the most devastating and surprising finales of the series so far, with a lot of fates left up in the air. Evidently, the Slough House team has never been given the help and support they needed, and this season, with the target planted firmly on their entire team, they took more of a toll than most in the midst of Diana Taverner’s deception.
With coinciding crisis’ that saw the return of River Cartwright’s father, Frank Harkness, the shocking reveal that Olivia Cooke’s Sid Baker was still alive, and the bloody shootout that decimated the team in the finale, this season stands out as the most challenging for the underdog heroes of MI5 to date.
However, despite all the hardship and challenges, Jackson Lamb and the rest of the team push on, and now that the season has ended and the trailer for Slow Horses season 7 has finally been unveiled, it’s worth considering what the future looks like for these characters, and what season 6’s ending means for the future of the team.
6
What Happened To River Cartwright In The Slow Horses Season 6 Finale?
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Jack Lowden’s River Cartwright has been stealing the spotlight from Gary Oldman’s Jackson Lamb since the series began, but as of the end of season 6, it appears that River is in a dire situation that shoves him out of the spotlight. After returning home from the brutal firefight that took place near Diana Taverner’s holiday home, River is thrilled to see the lights on in his late grandfather’s old home.
Having discussed the detail about his grandfather always leaving the light on for him with Sid earlier in the season, this appears to confirm that she is awaiting his return there after he helped her escape from the Russians. When he enters the house and hears the shower is on, he rushes to prepare some drinks, initially tea or coffee, before deciding to pour some wine to set the mood.
Unfortunately, before completing this ritual, River collapses to the ground. Considering Slow Horses season 6 adapts two of the books that the series is based on, Joe Country and Slough House, there is a clear answer that River has been poisoned. This appears to be the case in the show when he picks up the mysterious crowbar on the kitchen side before collapsing moments later.
In the books, Sid rushes River to get medical attention, endangering her own life, and both survive after being poisoned by the same virus that was mentioned as being used by the Russians earlier in the season. However, the show does not need to follow the books precisely, and with River’s presence being reduced in the subsequent novels, this could spell the end of his time in the story.
5
What Happened With Frank Harkness?
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Meanwhile, River’s hitman father, Frank Harkness, played by the extraordinary Hugo Weaving, was one of the major antagonists throughout this season as he was on a mission to eliminate the last witness of a hit he performed for a wealthy billionaire. Frank’s dogged determination led him to kill several people who got in his way, before being called off thanks to the clever ruse set up by Lamb and Diana Taverner.
Lamb forced the billionaire to call Frank off, which led to him returning to the house to say goodbye to River, and eliminate a Russian assassin, before River gave him a head start in escaping from the MI5 reinforcements. Evidently, given how skilled Frank has been at evading capture up to this point, he is likely still free and creating distance between himself and the latest job.
4
How Is Diana Taverner Keeping Her Job As First Desk Of MI5?
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On the other hand, MI5’s First Desk, Diana Taverner, appears to have successfully evaded all consequences for her misdeeds. This season’s drama has all spun out due to Taverner’s dodgy deals with billionaires and unwittingly taking money from the Russians. Thanks to Lamb’s quick thinking, Taverner was able to redirect the blame, and rather than confess to her compromised status, she was able to lay a trap for her benefactor.
Obviously, Lamb could have let Taverner march with her tail between her legs and face resigning as First Desk, but due to their ongoing professional relationship, and his ability to coerce and guide Taverner’s decisions, it seems as though Lamb wants to keep her exactly where she is.
Of course, Taverner has created an awful lot of stress for Lamb and the team at Slough House in the past, but there is hope that his leverage on her will now grant Lamb access to more resources and position his team in a more favorable spot going forward.
3
What Will Happen To Lamb And The Slow Horses After So Many Members Of The Team Have Been Killed?
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This leverage couldn’t come at a better time, because Lamb is down several team members after the struggles of season 6. Along with the tragic death of JK Coe, and the indeterminate fate of River, Slough House also lost their latest new addition, Emma Flyte, who was reassigned by Taverner as a punishment for her outspoken behavior while serving as the Head of The Dogs.
On top of that, Sid Baker continues to be on the run, and despite Louisa Guy’s briefly returning, the latest interaction with MI5 is unlikely to sway her away from a more safe and secure career beyond the public sector. That means that Slough House will need to continue to operate, with fewer agents, and fewer resources than ever before.
Lamb will continue to guide the misfit agents, and the surviving members of the team appear to be set to take on a bigger role as seen in the Slow Horses season 7 trailer, which heavily features Shirley Dander taking center stage as the main field operative of the team. And, of course, Roddy Ho will continue to offer guidance and tech support from his desk.
2
When Will Slow Horses Season 7 Be Released?
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One of the most thrilling aspects of Slow Horses is the fact that the show has stuck to a rigid release schedule since it began airing in 2022. Every year, the show releases a new season, with seasons 1 and 2 both releasing in the same year. On top of that, with seasons shot in advance, each finale tends to tack on a trailer for the next season, as was seen at the end of season 6.
In the last several years, Slow Horses has fallen into a routine of releasing a new season around September of each year, which means that season 7 will probably come out in September 2027, and the already confirmed season 8 will be filming ahead of that debut.
1
Will Olivia Cooke Return In Slow Horses Season 7?
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Sidonie Baker, played by Olivia Cooke, returned in season 6 for the first time since season 1. While several other characters have come and gone since then, Sid left a lasting impression, and her return was a very welcome surprise. However, there is no guarantee that Sid will be back in season 7 and beyond.
While the books do see Sid show up in subsequent stories, and her fate continues to be tied to River’s, her situation is extremely precarious. She has been marked as a target by the Russians, and MI5 has been more than willing to put her in the firing line on Diana Taverner’s orders.
After playing dead for several seasons, it was great to see her step out of the shadows, but future episodes will likely see her avoid the spotlight once again, or united with River in whatever his fate may be. That being said, it is highly likely that Slow Horses season 7 will at least answer questions about where River and Sid Baker are, which will better establish their chances of returning in the future.
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