Our Country’s Good review – Timberlake Wertenbaker revises penal colony epic for a new world

The curtain is a union jack, opening on to uncultivated land – sand, rock and trees. This is 18th-century Australia where Sydney is under construction, Indigenous communities are besieged by British colonial settlements and the Royal Navy is not only governing the land but also controlling their country’s deported convicts with an iron fist.

The flag re-emerges to remind us of Britain’s imperial history and this original deportation scheme for a community deemed criminal. As we learn, the convicts in this penal colony in Sydney Cove are more like victims – often young, impoverished and illiterate. They face penal correction, or the hangman’s noose, for minor crimes such as stealing a loaf of bread.

Based on Thomas Keneally’s novel The Playmaker, and inspired by a true story, Timberlake Wertenbaker’s drama explores the idea of theatre as a humanising and rehabilitative force as the convicts and their captors come together to perform a restoration comedy, which the colony’s governor hopes will have a “civilising” influence on them.

The play was written in 1988 but has been revisited by Wertenbaker: a character once called the Aborigine is now named Killara (Naarah) and her narrative role has been expanded, with additional vocals used on the soundtrack.

Directed by Rachel O’Riordan, the play’s debates on whether prison should be for punishment or rehabilitation are smooth and engaging. The drama touches on various characters as 2Lt Ralph Clarke (Simon Manyonda) recruits his motley cast of pickpockets, sex workers and officers. It is incredibly strong at points, but many of the individual stories, loosely wound around the play-within-the-play conceit, are barely resolved or left stranded by the end. The final scene is both heartening and a little too cosy, given the unforgiving climate in which these characters find themselves.

The gaps are, to some degree, filled by excellent performances from a cast that doubles up with agility as convicts and officers. Jack Bardoe gives a convincing turn as Harry Brewer, haunted by the dead man whose hanging he ordered, and smothering Duckling (Aliyah Odoffin, just as potent in her smaller part) with his controlling love.

Nick Fletcher is charming as the flamboyant pickpocket Robert Sideway, who brings much of the humour, while Ruby Bentall, as the shy Mary Brenham, slowly blossoms over the course of rehearsals and has a heartwarming romance with Clarke. Catrin Aaron captures the hardened convict Liz Morden’s steeliness in the face of her prospective hanging, vulnerability wavering just under the surface, and Finbar Lynch makes a sad-eyed hangman who becomes the pariah in the play-within-the-play.

Gary McCann’s set design and Paul Keogan’s lighting catch the lugubrious mood and the hard-scrabble existence. Visually the play has an epic quality, but it is set against a building intimacy between these characters.

There are tentative thoughts around home: the prisoner Dabby Bryant (Nicola Stephenson) constantly yearns to be back in the West Country and speaks of Englishness as a feeling, but others are already forming dreams and aspirations to make this land theirs. These moments – too short – suggest that even in the most extreme circumstances, people find a way to put down roots.

• At Lyric Hammersmith, London , until 5 October