Staged in the intimate Circle Studio, Tess Monro's direction of Captain Amazing is a spectacular showcase of the Citizens' acting intern Nicholas Ralph's dynamism and has been elegantly designed to extract the maximum effectiveness from minimal scenography: chalk, a wall and a couple of boxes are enough for the production to conjure the interior world of a man struggling with fatherhood, separation and the fragility of life. A monologue that alternates between fantasy sequences - the adventures of Captain Amazing - and more familiar relationship conflicts.

Monro's sprightly direction pushes Ralph through a range of emotions and characters: variously voicing a young girl, a petulant Batman, a drunk and desperate father, a naive young lover, Ralph is a powerful presence, embodying the characters and racing about the stage. The lighting design subtly divides between scenes, allowing Ralph to descend into the anguish of the hero, whether he is battling the evil villain or trying to explain divorce to his ailing daughter.

The script, however, is sometimes confusing: forcing the protagonist to play all the parts loses the momentum and coherence of the plot, and the relationship between his superhero fantasy and real life is at times tenuous. While it clearly signals a retreat in a childish attempt to make sense of the world, it isn't clear whether the Captain Amazing persona is an exaggerated enthusiasm for the comic book world or a mental illness. The tragic event at the climax is lost beneath the manic cosplay, and Alistair McDowall's script show little interest in exploring the superhero archetype beyond a general preoccupation with good and evil: the deconstructions of Superman and Batman, and the failure of the hero to save the girl, are addressed with much less sophistication than in most comics since 1961, when the Marvel Age under Stan Lee, Jack Kirby and Steve Dikto began the introduction of more naturalistic characterisation and mature themes.

Nevertheless, the central performance is impressive, bringing life to a story that is only sketched in the script and the scenography takes advantage of the stripped back style and smaller space to evoke a troubled mind in a world that it cannot resolve. A far from important script becomes an expression of a talented team that bring compassion, commitment and intelligence.

Reviewed at Citizens Theatre, Glasgow.