Star rating ** Heavy on atmosphere but light on substance, this slim piece follows the attempts of two eighteenth-century monks to deliver the bones of St Andrew to safety. It's billed as a comedy but really there's only one joke in Colin MacDonald's script: one of the two, Eardwulf, doesn't act like a monk at all. He drinks, swears, fights and sleeps with other men's wives. By contrast, the younger Osred is a virginal innocent.

The characters don't exactly develop during the 40-minute duration; instead, a last-ditch sacrifice serves as the conclusion to a frustratingly linear tale that lacks tension and purpose. It doesn't help that a huddle of hooded monks is constantly shuffling about or praying in the shadows, dragging down the pace without adding any sense of menace or hot pursuit.

Co-directors Marilyn Imrie and Rosie Kellagher have done their best with the material, and the set, music and lighting all strike just the right note, but ultimately the play itself is neither funny nor inspiring.

There are tentative references to big questions about ritual and religion (at one point Eardwulf declares St Andrew a false god and insists that he "believes in Christ, not bells and bones"), but his professed dedication to the faith is hard to reconcile with his actions.

Angus King brings plenty of bawdy energy to the proceedings as Eardwulf, but Mark McDonnell has his work cut out as the equally two-dimensional Osred and overplays his innocence, blinkered determination and pointless outrage at the behaviour of his partner in crime.