- Keira Knightley (Helen Webb)
- Ben Whishaw (Sam Young)
- Sarah Lancashire (Mrs. Reed)
- Andrew Buchan (Wallace)
- Ella Lily Hyland (Williams)
Episode: Black Door
Air Date: 2026-11-05
Runtime: 50 min
As her husband steps up as prime minister, Helen helps Reed steal files codenamed Wildflower and a shadowy organization coerces Sam into a contract.