Season 6 of Slow Horses opens with a death that has been building since the show began. David Cartwright, River’s grandfather, died off-screen before the season even started. The episode, titled “Circle of Life,” handles the news with restraint. It is a quiet, devastating shift.
David Cartwright was played by Jonathan Pryce, whose presence defined the early seasons of the Apple TV series. His exit from the show is a significant moment for fans who have followed the show since its debut. The death is not sudden or shocking — it is natural and peaceful. But that does not make it any easier to bear.
The Death of David Cartwright
River learns of his granddad’s passing in the first episode. Diana informs him about the funeral arrangements, explaining that security will be required at the service and that a fabricated backstory about David’s work for the Department of Transport will be used to keep the public at bay. The news comes as River is talking back to Taverner, who has refused bereavement leave and is exhausted from the case load.
The show makes it clear that David was the only true family River had in life. He was the closest thing River had to a father, and the care home costs had eaten all of his granddad’s funds. River calls his mother to leave another message asking if she is coming to the funeral, and the episode confirms that David was 83 years old when he passed peacefully in his bed.
The episode follows River through the grief process. He spends the night at his granddad’s house while rain pours down outside. He furiously shines his dress shoes, eats dinner in silence, and sips a beer while remembering the final conversation he had with David. Pryce appears in one final bittersweet flashback, showing David’s pain, fatigue, and mental decline as he asks a grown River why he isn’t in school.
In the final exchange, David tells River they will talk more before nodding off. It is a tender, tear-jerking moment that lands because the show has spent the entire series building this relationship. The two hold hands, and the scene is one of the most affecting in the show’s history.
The Funeral and the Speech
River goes into his grandad’s closet and buries his face in one of David’s old suits. He wears the suit to the funeral, where he delivers a thoughtful, hilariously transportation-coded speech about his granddad’s devotion to his work, love of people, and integrity. He gives the speech with a hand on the casket, saying goodbye to the closest thing he had to a father.
The speech is a highlight of the episode. It is funny and sad at the same time, a tribute that fits the show’s tone. The humor works because it is earned — the grief is real, and the levity is a release valve rather than a distraction.
Then comes the other shoe: River’s biological dad crashes the funeral for “business.” The episode ends on that note, leaving the question of what happens next open.
The Off-Screen Death
The episode is titled “Circle of Life,” and the title frames the death as part of a larger cycle. David’s death is not a sudden plot device — it is a natural progression of a character who has been aging throughout the series. The writers chose to handle it off-screen.
The episode also kills two former Slough House members, Struan Loy and Kay White, who were fatally attacked by assassins. But these deaths are secondary to David’s. They are part of the plot machinery, not the emotional core.
Why Pryce Left the Show
David Cartwright passed away prior to book six, Joe Country. The character’s death in the books preceded the adaptation, which means the show was always going to lose him eventually. But the timing of the episode suggests the show wanted to make this moment count.
Pryce’s performance was a major draw for the series. He brought warmth, wisdom, and a deep sense of humanity to the role. His chemistry with Jack Lowden, who plays River, was genuine, and the scenes between the two actors were some of the best in the show.
Will Smith, the creator and former showrunner of Slow Horses, praised Pryce’s work in a Season 3 post-mortem interview. “Jonathan doesn’t need to hear from me or anyone — he’s an absolute titan,” Smith said.
Smith also spoke about the scenes between Pryce and Lowden. “To watch Jack in scenes with Jonathan, you go, ‘Well, there’s no imbalance here. You guys are both bringing it,’ ” Smith said. “That scene of them in the club [in Season 3] is one of my favorite scenes we’ve ever done. I was watching that like, ‘Oh my god.’ I found it so moving, and I can see the tenderness from Jack and the pain that Jonathan’s going through as he processes what has happened and realizes what’s happening to him.”
“Jonathan doesn’t need to hear from me or anyone — he’s an absolute titan.”
The death of David Cartwright is a loss for the show, but it is also a chance to deepen River’s character. The grief will continue to follow and fuel him in Season 6 and beyond. The episode sets that up by showing River acting out after the funeral, pushed to the edge by the absence of his grandfather.
The Legacy of Pryce’s Performance
Pryce’s performance was phenomenal. He could nail charming, humorous moments and poignant, weighty scenes with equal care. He exuded warmth and wisdom effortlessly, and his chemistry with Lowden felt genuine.
The episode is a tribute to Pryce’s work. It lets the character die naturally, with dignity, and it gives him a moment of peace before the credits roll. It is a fitting end for a performer who brought so much to the show.
Key Facts Box
- Episode: “Circle of Life,” Season 6, Episode 1
- Character who died: David Cartwright, played by Jonathan Pryce
- Off-screen death
- Former Slough House members killed: Struan Loy and Kay White, fatally attacked by assassins
- David’s age: 83
- Cause of death: Natural causes
- Previous deaths: Sid Baker (Season 1), Min Harper (Season 2), Marcus Longridge (Season 4)
The Verdict
The episode is a masterclass in slow-burn storytelling. It does not rush the grief. It lets the audience feel it alongside River. The final flashback, the shoe-shining, the quiet dinner — all of it builds to a moment that feels earned.
The death of David Cartwright is a hard blow, but it is a necessary one. The show has stayed true to the novels, and the novels have always been willing to let characters go. This is a reminder that Slow Horses is at its best when it slows down. It is a reminder that the show’s strength lies in its ability to make us care about its characters, and then to let them go.
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