Diana is a woman of our days, whose daily routine is slowly distorted by listening to a radio drama that slowly brings her to a seemingly unknown and fantastic dimension to her.

A young girl swimmer, involved in an organisation with the aim of protecting dolphins, is engaged in an action against the local fishermen whose nets are endangering the creatures. She develops a rapport with some rescued dolphins, joining them in the society's tank, surprising other members with her ability to hold her breath for long periods. Following the death of a colleague, with whom she was in love, She decides to publicise the situation by breaking a world free-diving record.