In the last part of Zinnie Harris's trilogy of plays about international conflict we see a postwar country trying to do the right thing about its bloody past while struggling to found a new moral order. Fall's pressing central theme - the thin line between justice and revenge - is given extra urgency with the capture of Radovan Karadzic in Serbia.

Harris, a playwright who has also written for the BBC's political thriller Spooks, opens Fall with a 10-minute monologue (superbly delivered by Geraldine Alexander as Kate) in which we learn she is the widow of an executed war criminal desperately trying to understand his heinous crimes, of which she knew nothing.

Later, as civil unrest builds over the continuing executions, we see Kate being manipulated by Prime Minister Pierre and his deputy Howard (Paul Hickey), desperate to hold on to power, as they try to lay responsibility for their decisions onto her - the voice of the people. The once liberal Pierre, a puppet of the new regime, has his conscience pricked by a young activist but will he do the right thing - and what is the right thing to do anyway?

There's a lot of speechifying but little action or dramatic tension and the language never moves us sufficiently to care either way as Harris struggles to dramatise a complex, troubling moral issue. It's not helped by Dominic Hill's pedestrian staging and Tom Piper's grey-on-grey metallic set on an underlit stage. Hill, the Traverse's new artistic director, has good intentions but this production never takes flight.

The talented cast, led by Alexander and Darrell D'Silva as Pierre, give their all but this is theatre to be endured rather than enjoyed.

Until 24 August (0131 228 1404, www.traverse.co.uk)