The new journey begins when Sean Anderson receives a coded distress signal from a mysterious island where no island should exist — a place of strange life forms, mountains of gold, deadly volcanoes, and more than one astonishing secret. The secret is rumored to involve Sean's missing grandfather, Alexander Anderson. Unable to stop him from going, Sean's new stepfather joins the quest. Together with a helicopter pilot and his beautiful, strong-willed daughter, they set out to find the island, rescue its lone inhabitant and escape before seismic shockwaves force the island under the sea and bury its treasures forever.