Four years after leaving the lost island of Tamarind, Maya, Simon, and Penny Nelson return to stop the Red Coral Project, a sinister group mining the magical mineral ophalla there and, in the process, ruining the magnificent island.

Thirteen-year-old Maya, who has spent her life at sea with her marine biologist parents, yearns for a normal life, but when a storm washes her parents overboard, life becomes anything but normal for Maya, her younger brother and baby sister, as they land at a mysterious, uncharted island filled with danger.