A West Indian baby is discovered mid-Atlantic on the banana boat Il Mondo bound for the United Kingdom. Adopted in Lancashire and christened Dominique Alston, she grows up in 1950s Britain, a United Kingdom riddled with social, regional, and racial divides. Scarred in a racist attack at prep school, she moves to a boarding school in Sussex. But here, far from finding equality, the divides are reinforced.

Dominique's godfather, orchestra conductor Harold Goodall, is her guardian after the sudden death of her foster parents. At age eighteen, she starts work at The Mill House in Sussex. Gifted with a fine voice, she is to perform her premiere at the Chichester Festival. However, her Mill House duties are extensive, involving frequent voyages on the English Channel to fetch supplies. A visit to disfigured Caprice Capricciosa, Southdown lighthouse keeper, crystallises an underlying hope that she may one day find again her ocean cradle, the Il Mondo. But everything conspires to make the ocean not only her cradle but also her grave.