The Cartwright Family Storyline in ‘Slow Horses’ Reaches a Turning Point

Few families in ‘Slow Horses’ carry as much weight as the Cartwrights, and the latest season has reshaped that storyline in ways that matter for the whole series. David Cartwright is dead when the season begins, having died between seasons after a long decline with dementia. That leaves his grandson River to deal with the aftermath.

Anyone asking what happened to Cartwright is really asking about two characters, since David’s fate and River’s grief now sit side by side. The Cartwright storyline has moved from a quiet background thread to the emotional center of the season.

What Happened to Cartwright in the Premiere

The premiere makes David’s funeral the emotional center of the episode ‘Circle of Life.’ It opens with River arranging a ceremony whose public story cannot name David’s real career. The setup gives the loss a bitter edge, because the man being mourned cannot be honored for what he actually did.

River delivers a eulogy about his grandfather’s dull career in the Department of Transport, a moment that sends Jackson into fits of laughter despite the somber setting. It is a small scene, but it captures the mix of grief and dry humor the series is known for.

Jonathan Pryce still appears in the premiere through a flashback or dream sequence involving David and River. One reviewer said the flashback scene moved them to tears. The brief return gives viewers a last look at the character before the story moves on.

David Cartwright’s Fate and the Road From Earlier Seasons

The groundwork for this loss was laid before the premiere. The previous season showed the early deterioration of David Cartwright as old age and illness overtook his mind and body. River seemed visibly distracted and weary in that season’s first episode, and he appeared to make mistakes as his mind drifted elsewhere.

David had gone into a care home and was rapidly declining, and he was the only remaining member of River’s family. That context explains why his death lands so heavily in the new episodes. River has no relative left to lean on.

Critics have weighed the loss differently. The A.V. Club argued that David has largely worked as an accessory character, a reminder of Lamb’s nasty past and River’s stunted future. Pajiba took the opposite view, saying the death pushes the series to take River seriously and gives it an emotional depth it lacked before.

River Cartwright After the Funeral

The funeral does not end the story for River. He spots his estranged father, the dangerous American mercenary Frank Harkness, watching the service from a distance. River gives chase, but Harkness slips away before any confrontation, leaving his motives unresolved.

River stubbornly tries to stop Frank’s escape by jumping onto his car. As the confrontation ends, the assassins who have been picking off targets seem to settle on River as their next mark. The personal and the professional threats are now tangled together.

Speaking to TV Insider, co-executive producer Gaby Chiappe said David’s death leaves River “reeling.” She also said the tone of the show comes from the truly tragic and the truly ridiculous coexisting in the same moment. That balance shapes how River’s grief plays out.

Jonathan Pryce’s Exit and What Comes Next

Some viewers have wondered whether Pryce left the show on bad terms. The reporting says neither Pryce nor the production has announced a clash, a firing or a scheduling problem, and the exit follows the endpoint already built into David’s story. In other words, the character’s decline was always heading here.

The season also gives River more to carry. It draws on Mick Herron’s novels ‘Joe Country’ and ‘Slough House,’ and it reintroduces Frank Harkness as former Slough House agents begin turning up dead. One critic noted that River is put through the wringer physically and emotionally, and wondered whether his arc is about slowly becoming a Jackson Lamb.

Not every development is bleak. Sidonie Baker returned early in the season after being presumed dead, and her banter with River picks up right where it left off before she was shot in the first season. With David gone and Frank circling, River’s bond with Sid may become the steadiest thing he has left, so do you think that connection can hold the Cartwright story together once the season reaches its conclusion?