The first two plays in Ena Lamont Stewart’s revived trilogy seem peculiarly underdeveloped and creaking period pieces. Towards Evening, which premiered in Edinburgh in 1973, features a middle-aged brother (Robert Hands) and sister (Janette Foggo) who rub each other up the wrong way in a late-night encounter. He is cultured, pompous and feels smothered by her. She is resentful of being looked down on by him. It is rich in ideas but the dialogue is clunky: they speak in backstory, explaining their characters to one another.
The second, Walkies Time for a Black Poodle, is more complex but still led unsubtly by its issues. An insecure mistress of the house (Joanne Gallagher, convincingly rough around the edges) who has been made newly rich through marriage is in conversation with a domestic servant (Foggo) from a higher social class. It is a part confiding, part accusatory encounter but does not entirely convince as either.
Directed by Finlay Glen with a spare period set designed by Delyth Evans, both plays carry the potential for emotional intensity and explosions but don’t reach their peaks. Characters’ internalised voices are played as recordings rather than spoken live. It is an incredibly clumsy device; often, a character does little on stage while the recording tells us what they are feeling. This renders the action inert in already static conversational scenarios.
Stewart was Scotland’s first major modern female playwright and these plays introduce a new generation to her work – but feel like chamber pieces. What saves the production is the third play, Knocking on the Wall, first performed separately in 1978.
It again features siblings, two fractious sisters marooned with each other, but is more dramatically satisfying. Dorothy (Jasmine Hyde) was a teacher but is emotionally fragile and housebound. Isobel (Gallagher, again excellent) is an accountant who runs the home and leaves Dorothy feeling undermined. The arrival of a plumber instigates a fantastically compelling set-piece between his apprentice (Matt Littleson, amusingly gruff) and Dorothy. Their encounter is charged with class tensions and Pinteresque power play.
Hyde is especially masterful in steering the tone between awkward comedy and alarm. The delightful surprise of this last play makes the trilogy worth watching.
• At Finborough theatre, London, until 25 November