Gary Oldman’s fart-wreathed spymaster is back for London Rules, Roddy Ho steps into the spotlight, and production on Season 6 is already underway.
The slow horses have never moved this fast. Barely eight months after the explosive Season 4 finale, Apple TV+ is polishing the master for Slow Horses Season 5 of its Emmy-winning spy caper—and yes, Gary Oldman is still belching, belly-aching, and solving national crises in a stained overcoat.
Slow Horses Season 5
Below you’ll find every confirmed detail on the upcoming run, the books it will adapt, returning and new cast members, and the studio’s confidence in Seasons 6 and beyond.
Consider this your definitive Slow Horses Season 5 update as of May 2025.
Quick Status Check
- Production: Wrapped November 2024 (shot back-to-back with Season 4).
- Post-production: Final color pass completed March 2025; VFX lock in April.
- Release window: “Mid-to-late summer 2025,” according to showrunner Will Smith. Apple’s internal schedule pencils in August—just 11 months after Season 4 hit.
- Renewal horizon: Season 6 scripts finished; principal photography starts September 2025, adapting Joe Country and Slough House.
Apple likes the franchise so much it’s writing cheques for sets two seasons in advance—rare air even for the deep-pocketed streamer.
Source Material: London Rules Takes Center Stage
Slow Horses Season 5
Season 5 adapts Mick Herron’s fifth Slough House novel London Rules, in which a string of seemingly random terror incidents throws MI5 into code-red chaos.
First Desk Claude Whelan struggles to contain leaks while Diana Taverner tightens her grip on Regent’s Park. Over in Lamb’s purgatory office, personal demons collide: grief, addictions, a possible office psychopath, and an assassination attempt on the most unlikely target—Roddy Ho.
Slow Horses Season 5
Showrunner Will Smith promises the TV version sticks close to the book’s dizzying “24-hours-from-hell” tempo, while sprinkling new flashbacks that hint at Jackson Lamb’s Berlin days. Oldman teased to Radio Times: “The public will finally see why Lamb mistrusts German plumbing.”
Plot Threads Left Hanging After Season 4
- River’s Loyalty Test – Season 4 ends with River Cartwright at a pub table, apparently rejecting his father Frank Harkness’s mercenary offer. Season 5 opens the morning after, with River’s allegiance still under MI5 scrutiny.
- Diana vs. Whelan – Claude Whelan (James Callis) barely survived the Cicada scandal. London Rules pits him against a political black-ops smear campaign—perfect fodder for Kristen Scott Thomas’ steel-spined Taverner.
- Roddy’s Level-Up – Actor Christopher Chung confirmed Ho “gets louder, more self-assured, and maybe deadlier.” A glamorous girlfriend nobody trusts arrives in Episode 2; by Episode 6, Roddy is target number one.
- Lamb’s Health – Fans worried about Lamb’s chain-smoking heart will appreciate the new gag: a sugar binge after “too much cake,” sending him on what Smith calls “a diabetic James Bond rampage.”
Confirmed Cast List
Slow Horses Season 5
| Actor | Role | Season 5 Status |
|---|---|---|
| Gary Oldman | Jackson Lamb | Returning lead |
| Jack Lowden | River Cartwright | Returning |
| Kristin Scott Thomas | Diana Taverner | Returning |
| Christopher Chung | Roddy Ho | Promoted focus |
| Rosalind Eleazar | Louisa Guy | Returning |
| James Callis | Claude Whelan | Returning |
| Saskia Reeves | Catherine Standish | Returning |
| Aimee-Ffion Edwards | Shirley Dander | Returning |
| Kadiff Kirwan | Marcus Longridge | Returning |
| NEW: Celeste Dring (This Country) | Millie Taper—Roddy’s enigmatic girlfriend | Series regular |
| NEW: Greg Hemphill (Still Game) | Unionist firebrand turned TV pundit—central to terror plot | Recurring |
Showrunner Smith says Season 5 “expands the universe without leaving Slough House’s moldy carpet,” adding new Regent’s Park analysts and a rogue paramilitary unit that “makes the Frogs look polite.”
Tonal Tweaks: Laugh Harder, Bleed Faster
In post-production Smith found “two or three scenes where the laughs drowned the dread,” echoing creator Herron’s comedic-thriller balance.
The team tightened timing and music cues after test screenings. Expect sharper edit rhythms—fewer two-minute reaction shots, more smash-cuts to Lamb insulting someone’s mother.
Behind-the-Scenes Nuggets
- Cakegate: The “too much cake” gag required Oldman to eat 14 slices across multiple takes. Prop cake went gluten-free to spare him; still, he joked, “Lamb finally farted vanilla.”
- Budget bump: Apple increased per-episode spend by 15% for larger crowd scenes in Trafalgar Square and a night shoot on the Isle of Dogs canal.
- Herron cameo: Author Mick Herron appears briefly as a disgruntled bookseller refusing to stock Taverner’s ghostwritten memoir.
Trailer ETA
Traditionally, Apple drops Slow Horses trailers six to eight weeks pre-launch. If the August slot sticks, look for first footage in late June—likely timed to the premiere of another high-profile Apple drama to maximize eyeballs.
Will There Be a Season 7?
Oldman told press he’d play Lamb “until I retire or they kill him off.” Herron’s ninth novel Clown Town lands September 2025. Smith says Apple “has first refusal” on future books and that the writers’ room has “beat sheets through a potential Season 8.” Translation: as long as viewers keep turning out, the fart jokes and dead drops will, too.
