The sixth season finale of Apple TV+'s Slow Horses, titled 'Judgement Day,' sees the agents of Slough House once again in a perilous situation, facing pursuit and gunfire. Jackson Lamb orchestrates a plan for survival, while Reece Nesmith experiences a heroic moment utilizing a Chekov's harpoon. The episode also features a confrontation between River Cartwright and his father, Frank Harkness, suggesting a potential shift in Harkness's stance toward his son.
The season's conflict with Russian operatives concludes with the death of Clayface Jane and MI5 providing a scapegoat, though former agent Sid Baker is conspicuously absent for most of the episode. Despite the familiar survival stakes and the introduction of a major cliffhanger for Season 7, the finale adheres to a more conventional narrative structure than the series has typically employed.
Several plot points strain credulity, particularly Diana Taverner's sudden confession of treason after a season of denial, and Jackson Lamb's purported influence over her decision. The framing of Damien Cantor and Peter Judd as scapegoats for Russian-funded assassinations on home soil is presented, but the Home Secretary's swift acceptance of Diana's accusations without further investigation is questionable. While a teaser suggests Diana may face consequences, her immediate acceptance of responsibility seems abrupt.
Damien Cantor, positioned as the season's antagonist, ultimately proves less impactful than anticipated. His media influence is barely explored beyond a single viral interview, and his motivations, primarily a Russian media distribution contract mentioned only once, feel underdeveloped compared to the more complex antagonists of previous seasons.
The action sequences, involving chases and hiding in safe houses and a holiday home, contain moments of excitement. The necessity for the team to split up, however, hampers the narrative momentum, resulting in a stop-and-start tactical feel. Emma Flyte's sacrifice as a distraction and Louisa Guy's near-death experience are notable events, though Guy's survival was largely expected.
A more compelling development is the revelation of Harkness's motivations, particularly his potential decision to still pursue Reece after being called off by Cantor. His justification for Jane's death as self-defense feels insufficient, especially given his subsequent offer to share a drink with River. River's decision to let Harkness escape offers a poignant conclusion to their interaction and leaves the door open for Harkness's return in future seasons.
The final scene, set at River's grandfather's house, offers a moment of quiet reflection. Sid's promise to leave a light on is fulfilled, providing a bittersweet moment for River. The episode concludes with River's mysterious collapse after having tea and wine, raising questions about Sid's potential involvement or if external forces, like Jim and Jane, planted something that led to his incapacitation. The finale, despite its reliance on some predictable plot devices, successfully sets the stage for the upcoming seventh season.