Slow Horses season 5 episode 4 ending explained: JK Coe’s “accident” turns a mayoral debate into a crime scene

Slow Horses Season 5, Episode 4 “Missiles” lands on Apple TV+ as a midseason pivot that fuses political theater with slapstick catastrophe. The hour is directed by Saul Metzstein and written by Will Smith, continuing the adaptation of Mick Herron’s London Rules. The ensemble features Gary Oldman as Jackson Lamb, Jack Lowden as River Cartwright, Ruth Bradley as Emma Flyte, Saskia Reeves as Catherine Standish, Aimee Ffion Edwards as Shirley Dander, Christopher Chung as Roddy Ho, Nick Mohammed as Mayor Zafar Jaffrey, and Christopher Villiers as Dennis Gimball.

In Slow Horses Season 5 Episode 4, the unit splits across two rallies after an MI5 briefing flags the risk of a leader being hit. One event is for Jaffrey. The other is for Gimball. The episode’s hook is simple. Keep both men breathing. The ending breaks that bargain. A backstage scuffle, a scramble on scaffolding and a falling paint tin turn a debate warm-up into a fatal scene. The fallout frames the last two episodes.

What happens in Missiles: Ending explained and how Slow Horses Season 5 Episode 4 gets there

Slow Horses Season 5, Episode 4 opens with Flyte playing the role of an interrogator and empath. She feeds Roddy a story about a honeytrap who caught feelings, so he will keep Tara on the line long enough to trace her. He tries to warn Tara and hang up quickly, but the trace is still made anyway. Lamb is already a step ahead. He pulls taxi data from Tara’s calls and rides along, so he is present when Tara bolts at Roddy’s flat and gets grabbed. The show threads this with Park politics. Claude Whelan flips Dodie Gimball’s tabloid threat by arriving at the Gimballs’ home with a damaging personal history and a warning that their leverage is gone. The hour then splits the Horses. Catherine and Shirley attend Jaffrey’s rally. River and JK Coe cover Gimball’s event. At Jaffrey’s venue, Shirley notes a fake electrician’s combat boots. Catherine glimpses a shadow on a balcony and throws a bottle to force security to clear the stage. The rifle posing as a sealant gun never fires, and the mayor survives the attempt.

At Gimball’s venue, the fuse is lit by a private argument. Tyson from Jaffrey’s team asks Gimball not to use the candidate’s son in a speech. Gimball refuses and slings an insult. Tyson is pushed to react after Gimball remarks, “his lot” always leans on threats. River steps in with a gun, Tyson runs, and Coe leaves his perch to reach the alley. Coe’s descent knocks through a maze of props that jolt a paint tin loose. It drops straight onto Gimball’s head. The river ends up splashed with pink. The dictaphone on Gimball records the panic and the wordless realization that this death is on their watch. The pair scoop the recorder and leave because staying exposes Slough House and creates a crime scene run by enemies. The final image is not a mastermind pulling strings. It is a deadly accident that will read like a conspiracy. Slow Horses season 5 episode 4 uses that contrast to reset the case.

As the hour circles back to the Park, the episode also lets Lamb define the unit’s brand of failure. Lamb says,

“At least his lot f*** up on an epic scale.”

That fits the mess that follows and the cleanup to come. Slow Horses Season 5 Episode 4 also locks the season to a London Rules-style farce that underlines serious stakes. The paint tin gag is not played for laughs in the aftermath. It becomes the kind of bureaucratic nightmare that MI5 fears most. Two operatives on site. A weapon never fired. A candidate died anyway.

Why the accident matters now in Slow Horses Season 5 Episode 4

The ending of Slow Horses Season 5, Episode 4, is not an assassination by Farouk’s cell and not a sanctioned operation. It is Coe’s unintended act. That technical truth will not control the story. Optics will. Gimball had just faced a plea from an opponent’s aide. An MI5 gun flashed. Minutes later, a politician died via a chain reaction on set. The dictaphone is both a risk and a shield. It likely captures Tyson’s plea, Gimball’s refusal, River’s intervention, Coe’s shock and the empty sound of a can strike. That audio can anchor a timeline and still bury the unit if leaked out of order. Expect Lamb to trade the Park’s fresh leverage over the Gimballs to stop the worst narrative and box this as a tragic accident that occurred while agents were preventing wider harm.

Stay tuned for more updates.