A rescue mission leads Jay and Lila Cooper to a doomed South Sea island where nothing is as they expected. Instead of a primitive civilization, the Coopers encounter a busy colony with a mysterious leader claiming to be Adam MacKenzie, a missionary once presumed dead. To add to the confusion, someone seems to have pushed the island's self-destruct button. Earthquakes and erosion are tearing the island apart, and every moment is precious in the Coopers' search for the real Adam MacKenzie.