Bronson and Catherine Preminger, an elderly couple who loves sailing the seas in their huge yacht, are planning a suicide voyage to sink their beloved boat because of Catherine's memory-destroying terminal illness. However, their romantic plans to die together at sea are thwarted when their daughter, Brooke, announces they are to become grandparents.

Catherine wants to see her grandchild's face while her mind is still able to remember important things. She wants another wonderful memory to take with her to the deep. The couple sails to Bermuda instead with the intention of returning in time for the birth. However, two storms destroy their boat and they drift to a strange and unknown island where mysterious things start happening to them.

They endure unimaginable hardships trying to survive, but these hardships are not the only peril they are forced to suffer. They have an unknown and unseen enemy lurking about, trying to eliminate them from the island.

Can the couple withstand and meet the challenges presented to them? Better yet, can it be that they have found the Fountain of Youth halfway between Bermuda and Florida?