In considerably less time than it takes for Paul Chequer to tell Private Tommo Peaceful's short life story, three of the army's top brass briskly decided his fate at court martial. And there, in Tommo's undeserved death sentence, you have one of the rarely spoken-about horrors of the First World War: we shot our own men - many of them previously wounded, or gripped by what we now recognise as shell-shock - in order to deter any soldiers thinking of mutiny or deserting. Not that Tommo was a deserter. Or a coward. His moment of insubordination - in the face of an order to charge - was rooted in loving loyalty to his wounded brother Charlie and a realisation that any advance would be into direct fire from German guns.
In the event, he still faced a firing squad with Chequer's solo performance clocking the hours until dawn by remembering the joys and sorrows of an all-too-short life (like many recruits, Tommo was under-age when he volunteered).
Those who know the Michael Morpurgo book will soon detect the twist that Simon Reade has engineered in his staging of the tale. Nonetheless, the dark heart of the matter is powerfully encompassed in Tommo's increasingly soul-destroying experiences, as Chequer - on-stage with only an iron bedstead, a landscape backdrop and well-judged sound and lighting - voices all the characters with impressive ease.
If young audiences find the first half, with its idyllic vision of a countryside childhood, meanders into naive whimsicality, the second half - with its graphic evocation of the trenches vividly conjured up by Chequer - catches not just Tommo's shattered innocence but glimmers of the decent, caring man he might have become.
Repeated today at 11am and 2pm, and tomorrow at 11am; www.atgtickets.com/glasgow and 0844 871 7647 for bookings