Sally is a blue whale calf captured by the US Navy after her mother was killed by orcas (killer whales). She is raised and trained for military purposes by the Navy.Jo is a career US Navy officer. She is in her mid-twenties and has specialised in marine biology and submarine warfare.Paul is a thirty-something British doctor and single handed yacht sailor competing in a round-the-world yacht race.All three are brought together under extraordinary circumstances in the year 2025 and share an adventure in the Southern Hemisphere against a backdrop of ever-deteriorating relations between America and China and an increasingly dangerous world.