We will fix it, we will mend it. The words echo menacingly throughout Scottish writer and director Anthony Neilson's latest transfer from Edinburgh.

Abby and Stu are in love. Abby, a mature student, is pregnant, and the couple - whose relationship has become riddled with mistrust - must decide whether or not to keep the child and stay together. The reasons against - as relayed through lists, written messages passed back and forth, and 'Relate' questionnaires - overwhelmingly outnumber the reasons for. Yet the couple are driven to inaction by their love for each other - an unwanted sticking agent, like chewing gum on the bottom of your shoe.

And a dwindling relationship is not the only thing they're trying to fix. An ingenious manipulation of chronology reveals that - without wanting to give it away - what we are led to believe happened in the past is in fact the consequence, and an avoidant coping mechanism, of a tragic incident further on in time.

Morbidly bleak, sometimes darkly humorous, and unnervingly real, Neilson's script shines an unapologetic spotlight on love and mistrust, innocence and sexual fantasy, the cruel randomness of life and the human need to impose onto this some sense of order and responsibility. And it is not hard to see why this piece has caused such a stir; with references to child pornography, self-mutilation, and an indulgence of the sort of desires some may prefer to keep safely locked up in the subconscious.

Selina Boyack and Phil McKee are utterly compelling as the troubled couple, delivering their performances with a perfect balance of light and shade. Although with just a couple of passing references to this thing called 'happiness', you're left pondering on what exactly brought them together in the first place.

Perfectly complemented by Bob Bailey's stark set, the quietly nagging reminder of a ticking clock, and the slow wearing away of a chalked 'Stu 4 Abby' in the centre of the floor, Neilson's production is a chillingly accurate commentary on the darker side of human relations. A little less of the 'here's how you should be feeling at this point' music would be nice, but otherwise Stitching is most definitely one not to be missed.

- Peggy Nuttall (reviewed at London's Bush Theatre)