On one level W Somerset Maugham's The Sacred Flame is the archetypical well-made play of the late 1920s. On another, it's an equally archetypical whodunnit. On yet another, it's a detailed and truthful exploration of relationships – maternal and matrimonial, sexual and sublimated, caring and careless – which is just as valid for 2012 as for 1928.

Director Matthew Dunster and designer Anne Fleischie seem determined to keep us – the audience – at a distance. It's as though we are not meant, let alone wanted, to engage with the people on stage other than as actors playing their parts. Quite frankly, this intended alienation doesn't work; we do feel for the characters and we do become involved in their predicaments.

With the house lights still up and an oddly disturbing soundscape just impinging, stage managers move chairs and arrange props. Actors materialise for the first scene with paraplegic Maurice Tabret (the excellent Jamie De Courcey) in his hospital-type bed within a sort of cage framework. Wheeled into the main acting area by his devoted nurse Wayland (Sarah Churm), we discover from his conversations with the doctor, with a retired colonial police officer, and with his mother that he was a pilot who (just) survived a terrible crash.

Stella (Beatriz Romilly), the wife he wooed over Wagner's Tristan und Isolde, comes in from a performance of the opera; her escort has been Maurice's younger brother Colin (David Ricardo-Pearce). As Stella's reaction to this renewal of her relationship with the opera is revealed, so is the fragility of Maurice's own equilibrium. There is, of course, more to Stella's relationship with her brother-in-law than simple friendship.

By the beginning of the second act, Maurice has died (De Courcey remains on stage throughout) and accusations of a possible suspicious death start to be voiced. This is where Churm as the nurse, Al Nedjari as Dr Harvester and Robert Demeger as Major Liconda come into their own. But dominating the action is Margot Leicester as Mrs Tabert – the mother who sees further than anyone else in the family and has an apparently inexhaustible well of compassion on which to draw. It's a deeply moving portrait.

English Touring Theatre are to be congratulated in taking this play and treating it as seriously as did its author. It's just a pity that its attempted demolition of the theatre's “fourth wall” has made use of the wrong tools.