“STORIES don’t just end when you say they do,” says Declan in Kieran Hurley’s compelling two-hander. “They keep on going and they’re messy and they’re real.”

The final play helmed by Orla O’Loughlin as outgoing artistic director of the Traverse, Mouthpiece leaves you with uncertainty not resolution; a flurry of questions as you leave the theatre.

Powerfully performed by Lorn Macdonald (Renton in 2016’s Citizens Trainspotting reboot), Declan is a wounded teenager from a part of Edinburgh not on the tourist trail. Finding respite from society’s dismissal and turmoil at home, he’s taken to sitting high on Salisbury Crags, skillfully sketching the city sprawling around him.

It’s here he meets Libby (Neve McIntosh), a 40-something playwright feeling washed up and desperate. Both are lost and seek meaning and a place in the world. As their unlikely friendship develops, the unequal power relations of class show how different these worlds are.

However apparently well-meaning, Libby’s privilege blinds her to the harm she may be causing, and the fact that an appreciation of Francis Bacon will not give a vulnerable, forgotten youngster what he needs most – practical and substantive support.

Like Hurley’s Square Go, Heads Up and The Beats, Mouthpiece is sharp and veracious, with plenty to say – ironic considering that at its heart is an urge to address the ethical issues of making such a work. Here are questions that must be grappled with by those with notions about how art has the potential to make real life better. According to a scene here, it really can. That Mouthpiece also manages to entertain, provoke and surprise is the mark of a writer at the top of his game.

Until Dec 22 (not Mon, Sun), Traverse Theatre, Edinburgh, 8pm, mats Dec 13, 15, 20 & 22 2.30pm, £15, £8 to £12 concs. Tel: 0131 228 1404. @traversetheatre #MouthpiecePlay