Looking at children and childhood with an unflinchingly honest eye, the revival of Decky Does a Bronco by Edinburgh’s own Grid Iron proves to be an extremely welcome rematch indeed.

In the summer holidays of 1983, five boys, four aged nine and one aged eleven, turn their council estate swingpark into their own personal Utopia. The boys long to be grown up, mimicking the ways of the TV stars and action heroes they admire, but when tragedy strikes they are all forced into adulthood far too early, struggling to survive in the face of awful loss.

One of the boys, our narrator David, seems trapped in the past, unable to reach maturity as the other lads have. He tells the story, obsessing over details, observing but not directing the action of his playmates. He’s the heart of the story, and actor Martin McCormick switches chameleon-like between childish innocence and omniscient narrator, a demanding dual role carried off with aplomb.

That’s not to say that the rest of the cast can take it easy and let McCormick take the slack. David Elliot plays O’Neill as the effortlessly cool leader the kids all aspire to be, but behind his easy swagger is a child as easily hurt as any other. Ross Allan, as David’s older cousin Barry, is a mess of superiority and inferiority complexes, brought on by hanging around with younger lads but still being dependant on their opinions of him. And then there are Christy and Decky, rampaging around, fighting and yelling and generally being best friends as only boys can. Tiny Decky (a heartbreaking Ben Winger) can’t do a bronco, a trick on the swings that all the other kids have mastered, and their hilarity at his expense gives the play its title.

Site-specific specialists Grid Iron have really outdone themselves at the Scotland Yard Playground, building a swing set large enough to make the adult cast look small, and authentic enough not to seem out of place within a public park. The cast of trained acrobats clamber all over it like monkeys, hanging from the top beam, hooking their legs through the swing chains and dangling dangerously upside down, and, of course, broncoing like their lives depend on it.

Although the acrobatics are consistently impressive, it’s writer Douglas Maxwell’s realistic script that shines through, unsentimentally examining the nastiness and wonder of childhood with equal vigour. Although this is a play about childhood, it is most certainly not a work for children, and parents are advised that under twelves might find it too unsettling.

Riveting and original, make sure you pack a parka for this outdoor performance – you won’t want to miss a minute, despite Edinburgh’s unsettled weather.  

Traverse@Scotland Yard, 5-21 Aug (not 9, 16), 7.30pm