Slow Horses season 4 finale ending explained: What happens to Frank?

The finale of Slow Horses Season 4 starts on a tense note. An injured and dazed Emma Flyte receives a call from Diana Taverner. The former informs the latter that a single assassin has killed four of the Dogs and kidnapped River. The MI5 Second Desk, naturally, is alarmed to hear this.

Meanwhile, Patrice has brought River to Frank, his biological father. Thanks to River’s ingenuity, the Horses and the Dogscano track his current location. When they arrive at the spot, a chase ensues between them and Frank, culminating in Frank’s arrest. However, by the end of Slow Horses season 4’s finale, Taverner and company are compelled to let Frank walk out.

The finale was released on Apple TV+ on October 9, 2024. The synopsis of the episode, titled Hello Goodbye, reads:

“Season finale. Impossible decisions are faced and sacrifices are made.”

The finale grants closure to several plot and character elements throughout the season. However, plenty of loose ends are simultaneously present in the episode, teasing another season of the popular series.

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Slow Horses Season 4 finale: Frank is caught and then released

Episode 6 begins with Patrice bringing River to a restaurant where Frank is waiting for him. Frank acknowledges the biological tie between the two when he greets River as his son.

Frank offers River a position in his army of assassins since he thinks River is not appreciated enough at Slough House. Frank uses many personal and pragmatic arguments to lure River into agreeing to work with him, but River is unconvinced.

Further, while Frank is talking, River calls Louisa from Catherine’s phone, which he has been carrying since his trip to France. Using this, Ho tracks down River’s location. However, the Dogs have also found the same, thanks to some CCTV footage.

While the Slow Horses arrive at the spot to rescue River, the Dogs come to shoot him since Whelan has issued a shoot-to-kill order on River. However, upon arriving at the spot, the Horses and Dogs attempt to get hold of Frank, who uses River as a bodyshield to flee the place.

A hunt for Frank ensues. River, remembering a piece of advice Frank gave him a few minutes ago, stops running and enters a diner at the station. He sees Frank hiding there. The latter is swiftly arrested.

In the interrogation room, however, Frank confidently tells Taverner that she must let him go soon. Sure enough, Lamb tells Traverner that Frank plans to put MI5’s cold-bodies scandal up on the web if he is not freed within twelve hours.

Franks tells Taverner in the finale of Slow Horses Season 4 that he is just getting started. Thus, we might see more of him in the subsequent seasons of the show, especially since he has knowledge of MI5’s illicit operations, which could cause massive public uproar if made public.

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Marcus breathes his last in Slow Horses Season 4 finale

Upon bringing River to Frank, Patrice leaves to care for an unfinished business, killing David Cartwright. Patrice barges into the Slough House to do that, and a brutal shootout follows between him and the Horses.

The agents of the House are no match against the trained assassin. Their woe is amplified by the fact that, apart from Marcus, they do not have guns on them. Marcus fires back to hold Patrice’s rampage.

Meanwhile, the others try to find Lamb’s gun, which they do at the last moment. Marcus and Patrice keep exchanging bullets, followed by an ominous lull. Then, Patrice breaks into Lamb’s office and points a gun at Shirley. Lamb knocks out Patrice at the critical moment with a wine bottle.

When Shirley finds out that Marcus has lost his life in the gunfight, she almost ends up shooting a captive, Patrice. However, J.K. stops her before killing Patrice himself.

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What happens to David?

In the final moments of the Slow Horses Season 4 finale, River drives David to a home for elderly people. David’s mental health is failing, and River thinks this would be better for the old man since River is not able to spend as much time with David as needed.

David, however, thinks River is angry with him because he hid the truth about the latter’s father. He asks River to take him back to his house. However, River assures his grandfather that he will be back to see him the next day and leaves.

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Slow Horses has already been renewed for a fifth season, which will be based on the book London Rules. The finale of Slow Horses Season 4 teases some scenes from the next season, which will, interestingly, see Taverner and Lamb team up.