The Neptune Challenge - Polly Holyoke - Bog

Genetically engineered to survive in the ocean, Nere and her friends are tasked with infiltrating a high-tech undersea base to rescue two kidnapped children and to find the secret to saving the world's oceans, hidden somewhere deep inside the vast fortress. With bloodthirsty mutant sharks and savage kids roaming the corridors, Nere and her companions must find a way to save their friends, themselves, and their underwater world.