You couldn't accuse Des Dillon of lack of ambition. Monks, a reworking of his novel The Big Q, tries to make sense of sectarianism, mental illness, compulsive behaviour, faith healing, miracles and absolution. All with a generous helping of dry, working-class humour, and set on top of a mountain in Italy.
To his credit, it nearly works. In this comedy about two men who steal a schizophrenic patient from hospital in the hope that he can be cured by an Italian hermit, Dillon describes how life can cause mental damage to any of us. Paul Thomas Hickey's Jay is the most severely affected, suffering post-traumatic shock after murdering a member of the RUC, then being knee-capped and raped by the IRA. But not far along the spectrum are his father Pat, his friend Davy, Catholic pilgrim Suzanne and local landowner Jo, who have developed compulsive behaviour as a result of losing loved ones. In this, they seem no more neurotic than Fabian the hermit, whose remorse about a fatally failed miracle has led him to wear a ball and chain.
They have a "big empty feeling" that needs to be filled. And, despite a strand of Graham Greene-style scepticism - notably in Stephen McCole's ebullient Davy, a no-nonsense Protestant - Dillon allows the possibility of transformation through religious faith. His ending is irritatingly ambiguous, but seems to suggest a miracle has taken place. Though the characters approach a spiritual epiphany, it's hard for us to share their sense of resolution. Dillon holds back narrative details as if they were revelations in a whodunnit. By the time we have got to grips with every- one's dilemmas, it's too late to care.
· Until April 7. Box office: 0131-248 4848
