The Grass Arena is based on the autobiography of John Healy. Raised in an strongly religious family, with an abusive father, John soon learns that he has to defend himself. Growing into adulthood he takes up boxing, but soon falls victim to alcoholism. His boxing career over, John takes to the Grass Arena (the park) where he lives with other alcoholics. Prison time introduces him to a new and unexpected path.

The discovery of the world by a young boy singing "I spy with my little eye something beginning with..."