An emerging playwright often takes a few pieces to find a voice, an identifiable tone or style. Harry Mould’s debut play, The Brenda Line, already ripples with established characteristics that will no doubt echo through later works; a proficiency of language that roguishly toys with the divide between radical anger and refreshing wit. Staged in a simple yet effective set by designer Natalie Fern, Ben Occhipinti’s direction is evenly paced; its two-act structure works surprisingly well, much calmer and less intensive than suspected.

The youngest volunteer in the country, Karen, starts their first shift with the Samaritans helpline, having been paired with Anne, an experienced Samaritan and occasional ‘Brenda’ for what seems a slow night shift. The naturalistic banter of this pair, perceptively performed by Fiona Bruce and Charlotte Grayson, gradually extends to an endearing two-hander where the barbs and generational misunderstandings build with Karen’s revulsion at the ‘punctual perverts’, men who call the helpline and ask for Brenda: looking for company with a woman while they masturbate.

The work is balanced with nimble comedic writing, given tremendous welly and weight by Bruce and Grayson’s gorgeously human performances. Neither of the characters is entirely in the right, but both are lonesome; Anne’s humane outlook is as genuine as Karen’s intense vigour and politically charged (and lengthy) monologuing. There is no condemnation in Mould’s writing, giving a face to the women on the end of that telephone; this is a winsome debut from a playwright with a fair amount to say. Scottish theatre would be daft to miss this call.

The Brenda Line, Pitlochry Festival Theatre, until Wednesday 18 September; Traverse Theatre, Wednesday 13–Saturday 16 November.