Many of David Harrower’s plays are confrontational. They usually feature characters who, in the course of the work, explore their past. However, none so far that I know of cover a subject matter as delicate and as dark as Blackbird. As a religious symbol, a blackbird represents those who are tempted by carnal pleasure: this is an unspoken temptation which surges through Harrower's fascinating work.

In this powerful piece Harrower reunites two people. One, a man of fifty-six years old and the other a woman of twenty-eight. This does not seem out of the ordinary until a sininister truth emerges. Una has tracked down Ray – or Peter as he is now known – to try and piece together some of her life and find out why he sexually abused her when she was twelve years old and he was forty.

A play about the sexual abuse of a child is not an easy subject to approach, but director Katie Posner, with the help from a cleverly designed set by Lydia Denno, manages it. George Costigan as Ray and Charlie Covell as Una handle the subject sympathetically. Harrower's slow, deliberate language and sharp staccato dialogue help the actors to convey both their personal confusion and personal control.

The balance of power switches back and forth between the characters until it levels in a clinch, which Ray is now able to resist. The action takes place in an extremely messy staff canteen. The set consists of overflowing bins, piles of rubbish, and out of line tables and chairs which mirrors the real-life mess which the characters find themselves in, played out under stylish, harsh white strip lights. Nothing and no-one can hide and  Lydia Denno's unforgiving set brings that vividly to life.

Blackbird is a credible play and I can understand Una’s need to confront Ray and Ray’s revulsion in seeing her, but as hard as he tries to explain, nothing can justify his earlier behaviour. This is a cleverly worked, thought provoking piece which pushes the boundaries between right and wrong.

Blackbird is at the Tron Theatre, Glasgow, until the 19th of November.