Gwenno the dolphin, was ‘born and bred in Cardigan bay’; with the Sea Chorus she sings of the mystery of the sea, and the hopes she has for her little calf, which soon she will give birth to.
The Boatman gives eco-tours in his licensed boat so that tourists can dolphin watch. A Man arrives, looking for healing from the sea; he signs up for a boat trip and hopes that swimming with dolphins will ease his pain.
Gwenno swims with the nursery group of Cardigan Bay dolphins. Their main job is to learn how to hunt by playing, and she encourages them in their games.
The Man on his boat trip sees Gwenno swimming with her dolphins and jumps into the sea just as Gwenno gives birth to her calf. Gwenno and her baby are separated and she turns to attack the Man in anger.
The Boatman pulls the Man back into the boat, furious at his stupidity.
The Sea Chorus sings of an incoming storm at sea, the sea that ‘speaks only force, weight that kills, unclimable hills, and waves that shatter in shivers of glass’.
Gwenno and her Dolphins are thrown around in the storm and meet Lighting, a Spanish dolphin who warns them to be ‘very afraid’. He goes on to sing of the impact of pollution and how ‘dolphins drown in a man-made sea’.
Gwenno’s calf is stranded and the Man on the seashore is out desperately looking for her. Suddenly, the sea washes the calf to the Man’s feet and he is able to guide her back out into the sea to find her mother, Gwenno.
A final scene presents Gwenno and her dolphins happily playing out at sea, with the Man – having joined in running the Boatman’s tours – counting them, singing of all that he’s learned. The Sea Chorus sing of ‘corridors empty and the waves…hollow in deserted bays’ and how ‘the sea speaks of loss in a thousand tongues, the sea that never stops leaving’.