The Neptune Challenge

Danger lurks beneath. . . .

Genetically engineered to survive in the ocean, Nere and her friends are recovering from their treacherous journey to Safety Harbor, an undersea refuge founded by the scientists of the Neptune Project. But plenty of enemies prowl just outside the colony's boundaries, and when two of the children are kidnapped, Nere, her loyal dolphins, and the other Neptune kids must set out on an expedition even more perilous than their first.

Tasked with infiltrating the kidnappe...