Puck is the leader of a family of bottlenose dolphins known to researchers as The Beachies because of their unusual habit of catching fish by driving them through shallows to the shore. She is heavily pregnant with her eighth calf, Samu, but the baby is late and the seas are starting to fill up with hundreds of sharks, ever-ready to feast on newborns. Swimming with Puck as she waits for Samu's birth, are her surviving daughters and grand-daughters and a five-year-old son, India, who ought to have sought independence by now but seems reluctant to leave the family circle. Change and hazards lie ahead and with the use of the latest in miniature HD cameras, and underwater listening devices, this film grants viewers unprecedented insight into how dolphins live, including the earliest hours of Samu's life, how older sisters help to guard the baby against sharks and scenes which suggest: . dolphin mothers 'sing' to their unborn babies . unrelated females gather to greet new-borns . family ...