As Hitler's war looms, famous Australian artist Roland Griffin returns home from London with his family to live a simple life of shared plums and low-cut lawns in the suburbs. In the yard: a daughter, and a son, Hal, growing up with a preoccupied father who is always out in his shed stretching canvases and painting outback pubs. An isolated man obsessed with other people and places. Everything is a picture, a symbol. Even Hal, the boy in the boat, drifting through a strange world of Incredible Floridas. As the years pass, Roland learns that Hal is unable to control his own thoughts, impulses, behaviour. The boy becomes the destroyer of family. The neighbourhood is enlisted to help Hal find a way forward. Child actor, a clocker at Cheltenham Racecourse, an apprentice race caller. Incredible Floridas describes Hal's attempts at adulthood, love, religion, and the hardest thing of all: gaining his father's approval.