Subplots involve Kitty and Pat practicing dance moves to "Saturday Night," and Julian eventually sitting down for a game of chess with Robin . Cast and Production Alison Cooper Charlotte Ritchie Mike Cooper Kiell Smith-Bynoe Thomas Thorne Mathew Baynton Julian Fawcett MP Simon Farnaby Lady Fanny Button Martha Howe-Douglas Pat Butcher Jim Howick Robin / Humphrey's Head Laurence Rickard The Captain Ben Willbond Kitty Lolly Adefope Lucy (Guest) Jessica Knappett Critical Reception

The central plot kicks off when a woman named Lucy (played by Jessica Knappett) arrives at Button House claiming to be Alison’s half-sister. While Alison is initially reeling from the news, the ghosts have mixed reactions: Thomas is immediately infatuated, Kitty becomes territorial over her "surrogate sister" Alison, and Lady Button and Julian suspect Lucy may have sinister motives.

If you'd like to explore further, I can provide a breakdown of or a list of other episodes that feature deep-dives into the ghosts' pasts. Which would you prefer?