The episode "Hello Goodbye," Season 4, Episode 6 of Slow Horses, opens immediately after the terrorist attack on the Dogs, with Emma Flyte alive but in shock. The Slough House team is reeling from the violence and chaos of the attack, trying to regroup and respond to the ongoing threat posed by Patrice, the relentless assassin who has infiltrated their space.

Patrice, severely injured from previous confrontations--having been run over, shot, knifed, scalded by a boiling kettle, coshed with a bottle of whisky, and emotionally scarred by his upbringing--continues his violent rampage through Slough House. Despite his battered state, he remains dangerous and determined to complete his mission.

As the team scrambles in disarray, there are no sophisticated defenses or traps; instead, the agents react with panic, shouting, swearing, and dropping things as they try to evade Patrice. The atmosphere is chaotic and tense, reflecting the raw, unpolished nature of Slough House's operations.

Marcus Longridge, one of the Slough House agents, takes a critical decision to confront Patrice directly in an attempt to protect his colleagues. Marcus's actions are driven by a mix of desperation and heroism. He engages Patrice in a brutal fight, enduring the assassin's lethal attacks. Despite Marcus's efforts, he is ultimately overwhelmed and fatally wounded.

JK Coe, another Slough House operative, arrives at the scene and, recognizing Marcus's suffering and the futility of prolonging his pain, puts him out of his misery with a precise and professional execution--two shots to the chest and one to the head. This act spares Shirley Dander, Marcus's close colleague, the trauma of witnessing his death firsthand.

Shirley's reaction to Marcus's death is deeply emotional. The episode focuses on her grief and the impact of losing a close friend and teammate. JK Coe offers Shirley a poignant line: "He loved you and he wanted you to love yourself," underscoring the personal bonds within the team amid the violence.

Meanwhile, Frank Harkness, who is in custody, has a brief conversation with Diana, hinting at his likely release due to a blackmail failsafe he has in place. This subplot suggests ongoing complications and unresolved threats beyond the immediate violence at Slough House.

The episode closes with the team mourning Marcus's death but also acknowledging the harsh realities of their work. The final scenes emphasize the cost of their mission and the fragile nature of their survival, with the team battered but still standing.

Throughout the episode, the narrative maintains a focus on the raw, human responses of the characters rather than high-tech espionage tactics, highlighting the vulnerability and resilience of the Slough House agents in the face of deadly danger.

The ending of Slow Horses Season 4, Episode 6 ("Hello Goodbye") is bleak and somber. River Cartwright is rescued but the cost is high: several Slough House agents die, including Marcus. Frank Harkness, the antagonist, is captured but likely to be released due to his blackmail leverage over British Intelligence. The episode closes with River meeting Jackson Lamb in a pub to sign an account of his movements, highlighting the painful sacrifices and moral ambiguity of espionage at Slough House.

The episode "Hello Goodbye" opens immediately after a violent shootout that has left four Slough House agents dead and Emma Flyte unconscious. Emma wakes up disoriented and reports to Diana Taverner that a single attacker managed to ambush the convoy and kidnap River Cartwright, who is now the most important person in England at that moment.

Back at Slough House, the remaining team braces for an imminent siege. Moira leaves a voicemail on Chapman's phones warning that David is back in the building, signaling rising tension and danger within their own ranks.

Meanwhile, River is held captive by Patrice, the assassin connected to his long-lost father, Frank Harkness. Throughout the season, River has discovered his father is a mercenary who led a death squad composed of his own sons, all of whom have now died. River also had to place his grandfather in a care home, a painful family moment that underscores the personal costs of his spy life.

Frank Harkness is taken into custody by MI5, but he holds incriminating letters addressed to intelligence heads, detailing illicit assassinations carried out by his death squad for British Intelligence. He threatens to release these letters online if not released, forcing MI5 to let him go quietly to avoid a diplomatic crisis.

The episode focuses heavily on the emotional aftermath of the losses at Slough House. Marcus's death is particularly poignant, with the show emphasizing Shirley's grief and Jackson Lamb's attempt to shield her from the pain of seeing Marcus's body. This moment highlights the close bonds within the Slough House team and the personal toll of their dangerous work.

The finale ends with River meeting Jackson Lamb in a pub, where River signs an account of his movements that will earn Lamb an operational bonus. This quiet, almost mundane scene contrasts with the violence and loss that preceded it, underscoring the bleak reality of their espionage world--no justice, only painful sacrifices and moral compromises.

In terms of character fates:

• River Cartwright survives but is deeply affected by the season's events, including the loss of family and the burden of his spy role.
• Jackson Lamb remains the cynical, pragmatic leader, navigating the moral gray areas of intelligence work.
• Emma Flyte recovers from her injuries and continues her role at Slough House.
• Marcus dies in the shootout, his death deeply felt by the team.
• Frank Harkness is captured but will likely be released due to his blackmail leverage, remaining a dangerous figure.

The episode closes on a note of unresolved tension and sacrifice, emphasizing the harsh realities of espionage and the personal costs borne by those at Slough House.

There is no post-credit scene in Slow Horses, Season 4, Episode 6, "Hello Goodbye" (2024). The episode concludes with a series of emotionally charged, character-driven moments that serve as the narrative endpoint for the season, but there is no additional scene or teaser after the credits roll.

The finale's closing sequence focuses on the aftermath of the violent siege at Slough House. Jackson Lamb, visibly shaken by the loss of Marcus and the mortal wounding of Sam Chapman, finds Chapman's body in a quiet, somber moment that reveals a rare vulnerability beneath his usual abrasive exterior. This scene is underscored by Lamb's silent grief and the weight of his responsibilities to his team, even those he outwardly disparages.

Meanwhile, River Cartwright fulfills his promise to his grandfather, David, by moving him into an elder-care facility--a decision fraught with guilt and reluctant acceptance, as River grapples with the emotional toll of his family's fractured legacy and his own place within it. The episode's final images linger on these personal resolutions, emphasizing the show's focus on character over spectacle.

No additional narrative content is presented after the credits, and all major plot threads are resolved within the body of the episode itself. The absence of a post-credit scene is consistent with the series' tone, which prioritizes emotional closure and character development over teasing future storylines.

In the episode 'Hello Goodbye,' River Cartwright is abducted by Patrice from the Dogs' custody. He is later taken to a cafe in Granary Square, Kings Cross, where he meets Frank Harkness. The episode focuses on the intense action and plot developments surrounding River's situation.

Patrice's storyline concludes with him being killed by Coe. Before his death, Patrice had been severely injured, having been run over, shot, knifed, scalded by a boiling kettle, and coshed with a bottle of cheap whisky. Coe ends his suffering with a professional 'two to the chest and one to the head' shooting.

Harkness appears in 'Hello Goodbye' as River is brought to him by Patrice. Although Harkness is in custody due to his blackmail failsafe, his presence indicates that he still holds significant influence and power, potentially leading to his release.

The Slough House team reacts to the armed intruder, Patrice, with chaos and disorganization. The scene is described as involving yelling, swearing, running around, and dropping things, highlighting the team's ramshackle nature.

Marcus's death has a significant emotional impact on the characters, particularly Shirley. The show focuses on Shirley's reaction to his death, and Jackson's efforts to protect her from seeing Marcus's body demonstrate the close relationships within the team.

The episode "Hello Goodbye," Season 4 Episode 6 of Slow Horses (2024), is not family friendly and is rated for viewers 15 and older due to its mature content. It contains severe violence and gore, including multiple intense chase and shootout scenes with fatalities, which may be upsetting for children or sensitive viewers. The episode also features severe profanity, alcohol, drug use, and smoking, and frightening and intense scenes throughout.

Potentially objectionable or upsetting aspects include:

• Graphic and frequent violence, including killings and shoot-to-kill orders.
• Emotional distress related to character deaths and grief.
• Intense suspense and action sequences that may be frightening.
• Strong language and adult themes involving substance use.

There is no sex or nudity content reported in this episode. Overall, the episode's tone is dark, gritty, and emotionally heavy, making it unsuitable for children or viewers sensitive to violence and mature themes.