Apple TV+ debuts Slow Horses season 6 with a trailer that reintroduces Gary Oldman as Jackson Lamb and confirms an Apple TV premiere date of September 16, with Kristin Scott Thomas and Jack Lowden among the returning and supporting cast.

Olivia Cooke returns as Sidonie “Sid” Baker, continuing cross-storyline connections within Mick Herron’s Slough House universe and signaling familiar faces rejoining the saga.

Season 6 follows Slough House operatives on the run as Diana Taverner pulls them into a high-stakes game of retaliation and revenge.

Lamb urges staying “dark” and avoiding phones, while tension builds as Roddy Ho is seen trying to contact Lamb by cell.

The trailer hints at an intensified threat from an unknown adversary, suggesting the team must band together to survive.

River Cartwright faces a tense, eerie showdown with his father, Frank Harkness, underscoring the season’s personal stakes.

The trailer’s reveal is presented as a promotional surprise designed to excite fans, capitalizing on Cooke’s renewed visibility from House of the Dragon.

The reporting notes Disney owns ABC News and Hulu as part of the source context.

Slow Horses remains a darkly humorous espionage drama about a dysfunctional Slough House, with the trailer setting up a run-and-survive arc.

Multiple former Slough House members appear in the season, foreshadowing new or rekindled plotlines and tensions.

The piece places the trailer within Apple TV’s fall lineup, with spoiler-free viewing guidance for those avoiding early plot details.