It's as if Anne McKevitt has been called in to do a gothic makeover. The set is black on black, the floor strewn with grey confetti, a central seat like a giant, dark wedding cake by caterers from hell. The only lights are the stars in the blackest sky and huddles of candles dripping with foreboding.
You'd expect nothing less for a play by Horace Walpole, the fourth Earl of Orford and pioneer of the Gothic novel with The Castle of Otranto in 1765. Three years later he penned this tale of mother-son incest, never performed until now. The reason, we're told, is that its subject was too daring for its time, though the existence of earlier incest dramas ('Tis Pity She's a Whore springs to mind, as does Oedipus and his complex) suggests there might be other factors.
Maybe it's because the play is heavy, leaden and dramatically unsatisfying. The cast do their best to wade through Walpole's stultifying blank verse - and it's a shame this is all they have to work with, as there are some stunning performances, especially from Angela Chadfield as the Countess and Estelle Morgan as Adelisa, the child born of the incestuous relationship.
Walpole's target is not the mother and son's crime but clerical corruption, and this is one of the play's problems. The first hour is dominated by the relationship between the Countess and her priest, the sinister Benedict (Matthew Zajac), with the revelation of badness squashed into the last half hour. There is no easy relationship, or an especially convincing one, between these two aspects of the play. So when the full horror is revealed - Edmund, the son, has unknowingly married his own daughter and sister - its impact is sensational rather than emotional. Chadfield does a excellent messy suicide after much wailing, but we don't care. Adelisa gets sent to a nunnery, which will probably be more fun than this play.
Despite the strength of the performances and the evocative set, The Mysterious Mother is ultimately a bad advert for keeping it in the family, and a good one for leaving things undisturbed in the cupboard full of unperformed stinkers.
• Until February 24. Box office: 0141-429 0022.
