Read ‘Slow Horses’ Season 5 Final Script “Scars”

Editor’s note: Deadline’s It Starts on the Page (Drama) features standout drama series scripts in 2026 Emmy contention.

The Season 5 finale of Apple TV‘s Slow Horses marks the final episode for creator and executive producer Will Smith who left the spy thriller after five seasons. Smith, who has earned two writing Emmy nominations and one win for his work on Slow Horses, penned the closer, “Scars,” which saw Jackson Lamb’s (Gary Oldman) gang get to the end of the season-long hunt for a cell of Libyan nationals attempting to destabilize MI5 by wrecking havoc on London and using Slough House to do it.

While the cell was working on its end game — retribution for the UK abandoning their country after the fall of Muammar Gaddafi — so was Smith. “Scars” ends with a moment he says wasn’t in the original drafts but rather evolved during shooting. It involves Lamb (Oldman), the sly but smelly head of the ramshackle Slough House bunch originated in Mick Herron’s spy novels, whose own history and reasons behind his curmudgeonly ways has long been a mystery to his team.

The unscripted moment called back a scene from two episodes earlier. In it, while his team was being held in lockdown, Lamb related a uncharacteristically solemn story about a spy who was tortured in Berlin during the Cold War, and had his feet burned by the SS when he would not name names. The SS killed his pregnant girlfriend before they decided he didn’t know the name after all and let him go.

Lamb wove the story cleverly to signal to his team how to escape the lockdown (you can do a lot with a deodorizer spray and a Bic lighter, it turns out) but left a lingering question: was he that Berlin spy?

Cut back to “Scars,” where, as Smith writes in his intro, after contemplating whether other characters or just the audience would see the big reveal, he opted for the latter with a shot of Lamb’s scarred feet.

Smith explains the decision and speaks further about the finale below. His script follows. Slow Horses has been renewed through Season 7.

One of the challenges of returning TV is that it must be different but the same. There must be enough that’s familiar so that it still feels like the show, but enough that’s new so that it doesn’t get stale or predictable. The final episode of season 4 had seen an intense shootout in Slough House crosscut with mayhem at St Pancras station. So, the immediate challenge was how to top that. But our superlative returning director Saul Metzstein urged me to go the other way. To try and build a bigger set piece could feel self-conscious, the impetus for it would be coming from outside the show not from within the story. Bringing it down to a showdown between two people ratcheted up the tension as we know for sure that one of them will die and allowed us to focus on the underlying plot driver – the anger at Libyan nationals over Britain abandoning their country after the overthrow of Gaddafi. I love that a show which at first glance seems to be about a flatulent spy can also examine the perils of interventionism, the legacy of colonialism, toxic masculinity and the rise of the populist Right and the ineffectual Left.

“Slow Horses” has always had an action component, but I don’t think of it as primarily an action show, to me it’s a character show. I’m so proud that the final run of scenes is all dialogue-based, and no less dramatic for it. It’s so sad to me that River rings Louisa to tell her he’s going back to the park, it shows how lonely he is that the one person he calls is the one person who told him she didn’t want to hear from him. But he has nobody else. And then in the next scene we reveal that it’s not going to work out the way he thinks it is and that yet again he will be denied his reward. Louisa won’t ring him back quickly because she’ll be annoyed that he rang, and by the time she does ring he’ll have learnt he’s still stuck at Slough House and will be too embarrassed to take her call. And so, their messy will-they-won’t-they continues.

The episode ends with a moment that wasn’t in the original drafts but evolved during the shooting and in retrospect felt like we had always been moving towards it. In episode 3 Lamb tells a long story about an agent in post-Cold War Berlin being brutally tortured and his pregnant lover being killed in front of him. One of the tortures was having the skin burnt off the soles of his feet. It turns out the story was laced with clues as to how the Slow Horses could break out of their lockdown. And so, whilst the story feels true during the telling, its veracity is immediately thrown into doubt. But with Lamb you can never tell. I’d always said that none or all the of the story could be true and it could or could not have happened to Lamb. After we shot the scene Gary’s wife Giselle Schmidt suggested we see Lamb’s feet later and that they are brutally scarred. I loved this idea as for me it still doesn’t confirm the story, but it leaves you in no doubt that Lamb has been through horrible suffering and that at the very least he was drawing on a traumatic incident from his past to sell the story and distract his captors. We talked about how to reveal this. One idea was to have Catherine (who already has an inkling that the story may have some basis in fact) see him asleep with his sock off. There was also a version where
she sees this then as she goes Lamb’s eyes snap open and we know that he knows that she knows his secret. But in the end my preference was for this to be a secret between Lamb and the audience.

We ended up shooting it twice. The first time Lamb was sitting in his desk chair with his foot across his leg, but it felt quite awkward and felt like we were forcing the moment. Then Saul came up with the elegant shot you see, which hints that something might be coming but you have no idea what. The camera drifts down from Lamb repairing a hole in his sock with duct tape (something we took from Gary’s father-in-law) whilst on the phone to Taverner. At the end of the move, we see a shot of Lamb’s scarred feet, which for me it changes everything you know about the character and answers the question that is on the mind of anyone who encounters Lamb – “what is his problem?” To do it with a wordless reveal on Lamb’s feet in the final beat of the series felt particularly sweet as when I think of Lamb, I see him leaning back with his feet on his desk, that’s one of the key shots of him established from the beginning of the show. The answer to “what is his problem?” was hiding in plain sight the whole time, we just didn’t know it.

Read the script below.