Chicken of the Baskervilles

A butler disappears from a large estate, and Bulman's answer is to get himself hired as staff. But a butler is invisible in plain sight, the one person in a grand house allowed to be everywhere and noticed nowhere, and the disguise is a good one. The tramp act from the first series was preparation for this. The estate runs on rules nobody has written down, and Bulman learns them the way staff do, by getting them wrong once.

The title is a joke in the best tradition, pinching the Baskerville name and giving it a chicken. Murray Smith wrote it, William Brayne directed, and the episode is a proper country-house mystery in miniature: all closed doors and careful manners, with staff who know more than the family suspects. The disappearance is solved in good time, and the pleasure is in the doing, the hierarchies and sideways glances, the conversations conducted while carrying trays. The episode has a light touch with a dark subject, a vanished man in a house that prefers not to discuss it.

Don Henderson plays Bulman the servant with the same patient attention he gives Bulman the detective, which is the whole trick of the episode. The character has always understood that the best way to watch a room is from inside it, and the butler's role lets him do that with a tray in his hand. Siobhan Redmond's Lucy McGinty works the outside of the case, keeping the investigation moving while her partner learns the household's routines. The two sides of the inquiry keep meeting in the middle, which is the design of the piece.

The episode is the show at its most playful, and there is no shame in that. A bit of polish and a borrowed title, and an hour that goes down easily. The mystery is the excuse; the household is the entertainment.