David Leddy's Horizontal Collaboration - the title could mean sleeping with the enemy, or just sleeping around - comes with an audience health warning. We are told as we take our seats that each performance has four new actors who know nothing in advance, and have no idea what is about to happen.

This proves less exciting than it sounds. They are, in fact, a tribunal, of United Nations lawyers dressed in long black gowns. On they troop - Michael Blair, Nicole Cooper, Julie Duncanson and Tonderai Munyevu were my quartet - and sit at four desks with four laptops. "The youngest girl, the blackest girl, they rape her first." The pre-prepared texts are read with complete neutrality, the baton passed randomly from one to the other. There are no jokes here.

The case widens to include a car bomb, political assassination, the testimony of a white female pharmacologist who is an African warlord's wife, evidence of peacekeepers raping young girls, the head of a rebel army, a treacherous progress towards peace. It is a murky, miserable business, one that you would expect to stick out in stark relief to the flat diffidence of the presentation.

In fact, the actors create confusion of the wrong sort in stumbling along their lines and not sufficiently articulating exactly who did what to whom and where the buck stops in the escalation of crime and punishment. The style propagated by David Leddy's Fire Exit company is a digest of experimental nudges by the Wooster Group and Alecky Blythe's instant relaying of unfamiliar material. The trouble with this is that, contrary to the conclusion that such an approach would yield startling novelty of theatrical expression, the skill and sophistication required presents an insuperable obstacle.

This hour-long non-drama is part of a double-bill, the other Leddy show being a three-hour online political thriller, City of the Blind, made for smartphone or tablet. This, too, I'm afraid to say, deals in "real-life abuse committed by UN peacekeepers," and you might indeed be tempted to sample what Leddy claims is a new kind of ground-breaking drama for small-scale technology.

Horizontal Collaboration runs at the Traverse Theatre until 24 August

FOR MORE ON EDINBURGH 2014 VISIT WHATSONSTAGE.COM/EDINBURGH-FESTIVAL