The episode opens with Shirley confronting a near-fatal incident where she pushes Roddy Ho out of the way of an oncoming car, convinced it was an assassination attempt rather than an accident. She brings this suspicion to Slough House, where Jackson Lamb feigns skepticism but internally acknowledges Shirley's instincts might be correct. River and Shirley then follow Roddy to a nightclub, where they observe him dancing with a glamorous supermodel, raising questions about whether Roddy has been honey-trapped as part of a larger scheme.

Shortly after, a shooting erupts, escalating the tension and confirming the presence of a serious threat. The team begins to piece together that the violent events occurring across London are interconnected and likely orchestrated by a terrorist network. Lamb and the Slough House agents start investigating the pattern of attacks, focusing on the possibility that Roddy's new relationship is a cover for espionage or manipulation.

River recalls having taken a covert photograph of Diana Taverner meeting with a figure named Black during surveillance training. Lamb uses this information to confront Taverner by returning Duffy's car to Regent's Park, claiming it contains a bomb. This forces Taverner to negotiate, offering Lamb a way out that would result in his dismissal without charges. She also threatens Standish and reveals that Sid has died in hospital. Meanwhile, River sneaks into the area while Duffy's security team investigates the car, and confronts Webb, accusing him of deliberately feeding him false intelligence during a failed exercise. River and Lamb threaten to expose Taverner's covert operation to the Director General of MI5 and the press, leveraging the photograph as proof.

The team tracks Curly and Hassan to a location they initially believe to be a Norman castle, but Ahmed corrects them that it is actually a folly. Curly prepares to kill Hassan, but Lamb, River, Min, Louisa, and Roddy arrive to intervene. A brief shootout ensues between Curly and River, during which Hassan knocks Curly out with a rock. When a group called "The Dogs," acting on orders from Tearney, arrive intending to kill Curly and plant a weapon on his corpse to justify the killing, the Slough House team prevents them from doing so, defying orders from First and Second Desk.

Throughout the episode, the tension between Slough House and the official MI5 leadership, particularly Diana Taverner, escalates as the slow horses uncover deeper layers of conspiracy and manipulation within the intelligence community. The episode ends with the team successfully thwarting the immediate threat to Curly, but the larger network behind the violent events remains at large, setting the stage for further investigation and conflict.

In the ending of Slow Horses Season 5, Episode 4, the main characters confront a critical and tense situation involving a hostage and a violent antagonist. The episode concludes with a shootout where Hassan, the hostage, manages to knock out Curly, the antagonist, with a rock. The arrival of the "Dogs," a lethal enforcement group, threatens to kill Curly, but the Slough House team intervenes to prevent this, defying orders from higher MI5 authorities. Larry, another key character, is killed earlier in the episode, shot by the Dogs on orders from Tearney, who then stages the scene to justify the killing.

The episode unfolds with escalating tension as Curly, the antagonist, forces Larry and Hassan to a secluded woodland area at gunpoint, intending to carry out a beheading. Larry manages to free Hassan and attacks Curly with an axe but ultimately flees, allowing Curly, though injured, to recapture Hassan. Larry then attempts to escape to the sea port of Harwich but is intercepted and shot dead by the Dogs, a ruthless enforcement unit acting under Tearney's orders. Tearney also plants a weapon on Larry's corpse to fabricate justification for the killing.

Meanwhile, Curly prepares to kill Hassan outside what he believes is a Norman castle, which Ahmed, another character, points out is actually a folly--a decorative building with no defensive purpose. The Slough House team--Lamb, River, Min, and Louisa--along with assistance from Roddy, track Curly and Hassan to this location. A brief shootout ensues between Curly and River, during which Hassan knocks Curly out with a rock, turning the tide.

The Dogs arrive on the scene intending to kill Curly, but the Slough House team intervenes, preventing the execution despite orders from First and Second Desk, the higher MI5 authorities. This act of defiance highlights the team's commitment to their own moral code and their willingness to challenge the official chain of command to protect lives.

At the episode's conclusion, the fate of the main characters is as follows:

• Larry: Killed by the Dogs at Harwich, his death staged to appear justified.
• Curly: Captured and knocked out by Hassan, saved from execution by the Slough House team.
• Hassan: Rescued from imminent death, instrumental in subduing Curly.
• Slough House team (Lamb, River, Min, Louisa, Roddy): Successfully intervene to save Hassan and prevent Curly's extrajudicial killing, demonstrating their resourcefulness and moral resolve.

This ending scene-by-scene narrative emphasizes the complex interplay of loyalty, betrayal, and moral ambiguity within MI5, as well as the Slough House team's role as reluctant but principled operatives navigating a corrupt and dangerous intelligence environment.

There is no information in the available search results indicating that Slow Horses, Season 5, Episode 4 (2025) has a post-credit scene. None of the sources, including detailed episode reviews, recaps, or production notes, mention any post-credit or after-credits scene for this episode.

If a post-credit scene existed, it would typically be noted in episode recaps or reviews due to its narrative significance, but no such mention appears in the sources found.

In Season 5, Episode 4, Roddy Ho is central to the plot as he is compromised by a glamorous femme fatale, leading to a lockdown of the Slough House. This episode highlights his vulnerability and the consequences of being caught in a honeytrap, which significantly impacts the team's dynamics and the unfolding investigation.

During the lockdown caused by Roddy Ho's compromise, Jackson Lamb tells a story to his colleagues that serves as a metaphorical guide on how to escape the MI5 muscle called The Dogs, who are guarding them in the office. This showcases Lamb's leadership and his ability to use wit and storytelling to manage crises within Slough House.

The sniper case introduced in Season 5 is a complex mystery involving Rob, whose death is revealed not to be self-inflicted. Emma Flyte discovers a shell casing on the rooftop, suggesting the sniper is taunting MI5. This case is larger than a single act of violence and involves a network of criminals, complicating the investigation and potentially drawing Slough House into the mix.

River Cartwright recalls taking a covert photo of Diana Taverner meeting with Black during surveillance training, which becomes a critical piece of evidence. River confronts Webb about Taverner feeding him incorrect intelligence to cause his demotion. This tension highlights the ongoing rivalry and mistrust between Slough House agents and MI5 leadership, particularly Taverner's manipulations.

In Episode 4, Curly prepares to kill Hassan outside what he believes is a Norman castle, which is actually a folly. Lamb, River, Min, Louisa, and Roddy track them to this location. A brief shoot-out ensues between Curly and River, ending with Hassan knocking out Curly. The Dogs arrive to kill Curly, but the group prevents this, defying MI5's First and Second Desk orders. This sequence underscores the internal conflicts and moral complexities within the spy operations.

The TV show Slow Horses, including Season 5 Episode 4 (2025), is not family friendly and is rated TV-MA, indicating it is intended for mature audiences only. It contains strong language, moderate to severe violence, and some sexual content, making it unsuitable for children or sensitive viewers.

Potentially objectionable or upsetting aspects include:

• Severe profanity: Frequent use of strong language including multiple f-words, s-words, and other harsh insults and slurs throughout the series.
• Moderate to graphic violence: Scenes may include bloody gunshot wounds, fights, and occasionally graphic depictions of violence such as severed heads and close-range shootings.
• Mild sexual content and nudity: Brief scenes involving underwear, passionate kissing, and adult-themed settings.
• Alcohol and smoking: Characters frequently drink alcohol and smoke.
• Intense and frightening scenes: Moderate intensity in suspense and thriller elements that may be unsettling.

Overall, the show's dark tone, explicit language, and violent content make it inappropriate for children and potentially distressing for sensitive viewers.