Mark Bailey transforms The Other Room stage into the cobbled streets of 1950s Edinburgh for Seanmhair, the second of three plays in the Outliers season. In some ways, this is a fitting companion piece to Sinners Club. If the latter is about how painful love can be when it’s betrayed, then Hywel John’s thriller is about how powerful it is when its unshaken.

Three supremely talented actors play the same role, that of Jenny, at different stages of her life. She recounts the passionate lifelong love affair she begins with Tommy at the age of ten, and the chaotic circumstances under which they unite.

An inevitability to the story borders on predictable but, ultimately, it’s not the narrative that will be remembered here. What makes Seanmhair such an enduring piece of theatre is the sheer beauty and intensity of its writing. There is an intricacy to John’s use of rhyme and repetition that, when juxtaposed with the harshness of his characters, leaves the audience riveted.

Other than an oddly-staged dream sequence (that, arguably, was unnecessary anyway), Kate Wasserberg’s direction is typically brilliant. The biggest challenge this production had was making sure the complex narrative structure didn’t get confusing but her crew help ensure that doesn’t happen. Katy Morison’s dingy blue lighting and Dyfan Jones’ haunting score gives Bailey’s stunning set design an ethereal quality, while the cast give captivating performances. Molly Vevers is wonderful as the innocent and impressionable ten-year old Jenny, but it’s Sian Howard who really steals the show as the older Jenny, withered by life and longing for her youth. Hannah McPake’s time as Jenny is the shortest, leaving her to embody the other characters in the play. Large, piercing eyes bring a frightening quality to her portrayal of Tommy, but a tenderness brings humour to Jenny’s father.

There is so much to like about this production, and so little to criticise. While it may certainly be a thriller – and a dark, somewhat controversial one – Seanmhair is, at its core, a carefully crafted piece of music. And not a note is put wrong.