Major Shake-Up for Slow Horses Season 6 — Here’s What Understood-But-Unsaid Departure of Showrunner Will Smith Really Means

The hit Apple TV+ spy thriller Slow Horses is barreling into its sixth season, but behind the scenes a big change is underway. Its creator and long-time showrunner Will Smith (not the Hollywood actor, but the Emmy-winning writer) will not be returning after Season 5. Here’s everything you need to know — from his own words — about why he left, what it means for the show’s future, and why fans should both worry and hope.

Why Will Smith Is Stepping Aside

Smith revealed to TheWrap and other outlets that his exit wasn’t born from conflict, nor from dissatisfaction — it was simply a practical decision about sustainability. TheWrap+2SlashFilm+2

He explains:

“It wasn’t a decision. It was a practical acceptance of reality.” — Will Smith TheWrap
“As the deadlines for Season 6 approached, it was clear I was never going to be able to get the scripts done … When we were doing the writers’ room for Season 5, it was at the same time we were editing Season 3 and [shooting] Season 4.” SlashFilm+1

In short: Slow Horses has been running at a blistering pace. The show produces seasons quickly, writes while filming, edits while another shoot is happening. Smith admitted he reached a point where he simply couldn’t keep up. SlashFilm+1

He also said:

“It was with great sadness on both sides, but I sadly couldn’t keep going.” TheWrap

And perhaps most surprising: he chose a clean break.

“I thought it was best to just [step completely away] … It’s someone else’s now. I can just sit back and watch it as a fan.” TheWrap

What This Means for Season 6 (and Beyond)

Smith is leaving just as Season 5 wraps up major story arcs — a timing he says “felt right”. SlashFilm+1

• The series has already been renewed for Season 6 and Season 7. EW.com+2Wikipedia+2

• Smith confirms the show’s in good hands: he praises the cast, production team and source material (novels by Mick Herron) as capable of carrying it forward. TheWrap+1

• According to reliable sources, the writing reins for Season 6 go to Gaby Chiappe, with Ben Vanstone lined up for Season 7. SlashFilm

So what should fans expect?

• Some changes in tone and perhaps structure as new voices come in.

• But the core of Slow Horses — the misfit MI5 spies at Slough House, led by Jackson Lamb (Gary Oldman) — remains firmly intact.

• Story-wise, Smith leaves at a pretty natural narrative juncture, so the transition might feel smoother than many network shake-ups.

Why This Isn’t Just “Another Showrunner Leaves”

There are a few reasons this matters more than usual:

• Slow Horses shot seasons at an unusual clip — often writing one, editing another, and filming a third simultaneously. That kind of hyper-production is rare and was a big factor in Smith’s departure. SlashFilm+1

• Smith had been showrunner from the very start, helping define the tone, pacing and character-voice of the series. His hand is deeply embedded in what made the show what it is.

• When someone who is so integral steps away, the risk of a “loss of mojo” or slip in quality is higher. Fans are paying attention.

• On the flip side: Smith’s exit at the right time could be a positive — avoiding creative fatigue, allowing fresh creative leadership while the series still has momentum.

If you’re a fan of the show:

• Don’t panic. The show is renewed, the cast returns, and major arcs are being handed off cleanly.

• But do stay alert. The new showrunners have big shoes to fill. How they handle Lamb, River, Taverner and the rest will determine whether Season 6 feels like Slow Horses as you know it — or something slightly different.

• Keep an eye on announcements: What is the premiere date for Season 6? How will the tone shift? Will the production pace remain as aggressive?

In essence: this is a bittersweet moment. Slow Horses is not ending — far from it — but one of its founding pillars is stepping aside. That change in itself becomes part of the story.

Curious about the full interview, Smith’s exact words, and how the show stacks up going forward? Make sure you read the full article to get the full picture.