It is 1963. Nine-year-old David and his friends spend the summer in the swing park, little boys learning to be men, testing themselves and each other as they undertake feats of daring.

The height of achievement is doing a Bronco: swing standing up and when you are level with the bar, kick the swing over your head and jump underneath it while it wraps itself around the bar. Everyone can do it except wee Decky.

Douglas Maxwell's bittersweet play, written in a sweet, dirty vernacular that details both the innocence and knowingness of childhood, takes the form of a memory play that questions the very nature of memory, guilt and our desire to make tragedy mean something.

With the sounds of real children playing nearby, Grid Iron's superb production, which takes place outside in the George V Park in Canonmills, is all the more poignant, detailing through adult actors the wild, restless unfocused energy of small boys. Grid Iron is unsurpassed in its ability to create site specific work in which there is a perfect marriage of site and subject. They score full marks here again, although in the open air they have their work cut out to ensure that the energy doesn't float upwards.

This is a slight but precious piece of theatre that captures all the fragility of childhood in the blink of an eye and the image of a small boy in a striped T-shirt launching himself off a swing into thin air. Flying, not falling.