The story
Slough House is where MI5 dumps its failures: agents who messed up badly, but not quite badly enough to be sacked. Their boss, the slovenly and gleefully insulting Jackson Lamb, expects boredom to drive them out. Yet these 'slow horses' have a habit of stumbling into operations that threaten national security, and into the murky politics of the service that rejected them.
Why it matters
Adapting Mick Herron's Slough House novels, Slow Horses has kept up a rare one-series-a-year rhythm by shooting two series back to back, while winning Emmys for writing and directing. Critics have praised its consistency across all six series, making it one of Apple TV's most reliable British dramas and a showcase for Gary Oldman's Jackson Lamb.
Notable facts
- Production shoots two series back to back, so the next series has finished filming before the current one is released. (source)
- Each of the first five series adapted one Slough House novel in order; series six combines Joe Country and Slough House. (source)
- Showrunner Will Smith stepped back after series five, with Gaby Chiappe taking over as head writer for series six. (source)
- The sixth series was previewed at the 2026 Toronto International Film Festival before its Apple TV release. (source)