Peter Ashbury is a young man who lives on Palm Beach, Sydney, with an expensive wife Mary and house he cannot afford. Their neighbours and close friends are Liz and Charles Barcher. He makes a £25,000 bet to murder Liz, the wife of the wealthy Charles. When the wife dies, blame attaches to Peter and then to his wife Mary.

This film takes the form of a psychiatric session, using the metaphor as a way to explore the wonders of the Great Barrier Reef.