The sixth season of Apple TV's spy drama Slow Horses has wrapped up with a finale that left viewers stunned. The closing moments appear to show the death of a central character, River Cartwright, and the show's new showrunner has now offered an explanation of what happened. Apple also released the first trailer for season seven.
Spoilers follow for anyone who has not yet seen the finale.
Character deaths have been a hallmark of this season, and the finale continued the trend. Emma Flyte was killed by Frank Harkness, River's father. But it was the final moments of the episode that delivered the biggest surprise, as River himself seemingly dies. What exactly caused his death is not made explicit on screen.
Head writer and season six showrunner Gaby Chiappe addressed the question in an interview with Gold Derby. She said the groundwork was laid in the second episode, when the assassins Jim and Jane, played by Kyle Soller and MyAnna Buring, come to a door while River and Sid are hiding. Jim looks around, notices a small bottle on a table, and sees the crowbar River had brought in with him.
According to Chiappe, viewers are meant to assume that Jim coats the crowbar with the contents of the bottle. Given the nerve agent attacks that have occurred elsewhere, she said, it is a Novichok attack.
The writers debated at length whether audiences would recognize what was happening. The idea comes from the source novel, though with a difference: in the book, the poison is left on a doorknob. Chiappe said the intent remains the same, that something happens at the edge of your vision without you quite understanding it. She added that the assassin who laid the poison is long dead by this point.
Chiappe did not formally confirm that River is dead. However, the season seven trailer, which aired at the end of the finale and was shared by Apple TV News Hub on X, strongly suggests that is the case.
The series has a long future ahead. Apple recently announced that Slow Horses has been renewed through season eight. Season seven has already finished filming, and its release is expected in or around September 2027.
Apple TV costs $14.99 per month, and is also available at a discount as part of the Apple One bundle.
