In 1856, a British clipper ship sinks after a storm while transporting convicts to an Australian penal colony. After horrible carnage on a raft, the pitiful survivors, among them Betsy Fletcher and Jess Dorsett, are washed up on a solitary tropical island, where they discover an immense source of diamonds and found a powerful and wealthy dynasty.

One hundred forty years later, Maeve Fletcher, one of their descendants, is stranded on an island in Antarctica with a party of passengers after their cruise ship seemingly abandons them. Dirk Pitt, on an expedition to find the source of a deadly plague that is killing dolphins and seals in the Weddell Sea, finds Maeve and the passengers and rescues them from death.

When Pitt later uncovers the cause of the plague, he discovers that Maeve's father, Arthur Dorsett, and her two sisters are responsible because of their diamond-mining technology. A deadly race develops to stop Dorsett from continuing his murderous mining operations and to head off a disaster that will kill millions.

Pitt's struggle to foil Dorsett's ruthless plan to destroy the market for diamonds and thus gain a monopoly of his own takes him from harrowing adventures off the west coast of Canada to being cast adrift in the Tasman Sea in a small boat with his good friend Al Giordino and the lovely Maeve Dorsett.