South Africa, 1976. The setting of this new MTC commission immediately puts the audience on edge, because that place and time means apartheid.

Destiny grapples with this official policy of racial segregation from the perspective of several “coloured” characters – the classification for people of mixed race, which determined everything from where they could live to who they could marry.

It’s politically charged, but this family drama written by and starring South African-born Kirsty Marillier is also rich with humour, heartache and tenderness.

Perfectly cast, including with two other actors of South African heritage, and grounded by an inventive set, the world premiere production of Destiny is directed by Zindzi Okenyo (co-director of MTC’s Is God Is).

Destiny. Photo © Pia Johnson

Marillier plays Della, who tries to keep her widowed dad Cliff from overdoing the booze, and her younger brother Rocky out of trouble – especially when her ex, Ezra, suddenly returns home from university. He’s a political activist, just like his late father, and smitten Rocky wants to join the cause.

Having long struggled to heal her broken heart, hold her family together, strive for a better life and keep her head down in an unjust society, Della fears everything is about to fall apart.

Marillier’s script is, like her pivotal character, restrained – dramatically speaking at least, because at times its cheekily funny. There are only a few crises, with momentum mostly generated by the relationships’ back and forth, and a slowly rising sense of authoritarian threat.

Before that kicks in Destiny’s 100 interval-free minutes sag a little, but for the most part its well-paced, intriguing storytelling.

Despite her wavering South African accent, Marillier’s interpretation of Della draws us into the family, as it were. Her looks and gestures suggest pent-up emotion and energy.

Destiny: Barry Conrad and Kirsty Marillier. Photo © Pia Johnston

Barry Conrad nails Ezra, an attractive, intelligent young man who oozes a charming kind of confidence. Gaz Dutlow charms in a different way as Rocky. They capture this teen who has a dawning realisation of queerness through lightly comic nervousness, mini drama-queen moments and bursts of joyful dance moves.

Patrick Williams is understated as Cliff, giving us a man of quiet nobility who has literally and figuratively been worn down by circumstances. He surprises with some beautiful unaccompanied singing near play’s end.

In two small roles, the cast is rounded out by Clare Chihambakwe as Ezra’s no-nonsense mother, and John Shearman’s white policeman who wields power like a dangerous toy.

Clare Chihambakwe and Kirsty Marillier. Photo © Pia Johnston

Sophie Woodward’s set cleverly conjures different, seamlessly connected spaces. The main focus is the family’s living room, which segues to the front yard, which leads out into the town via the wings and a few diagonal walkways upstage.

There’s a remarkable sense of movement and space whenever a cast member steps or cycles along these walkways, usually to the elevated set of the general store where Della works and telling one-on-one conversations occur.

Warmly lit by Kelsey Lee, Woodward’s set and costumes are gently located in time and place through a 1970s colour palette that’s often faded, suggesting bright sun and straightened circumstances. She does have some fun with the era, however: some flares here and an afro wig there for Conrad’s cool Ezra.

Destiny looks back on a recent chapter of history that already feels remote (though almost certainly not for South Africans). Zeroing in on a handful of characters living under apartheid, this play reminds us of the system’s injustice and terror, and the often unbreakable strength of human relationships.

Destiny plays at The Sumner, Melbourne, until 13 September.