After a day of hot-air ballooning is ruined by a recurring quarrel, Jake and Rinah Richardson drive head-on into a fierce summer squall on Long Island’s North Fork. Blinded by the flash storm, Jake inadvertently veers onto a narrow road to a small out-island, where they become stranded for the night. Already furious at him, Rinah adds this blunder to a growing list of offenses. Soon they realize there is something aberrant about the island and they must get off before it is too late. Now Jake has to call on his cunning and creative resourcefulness to figure out a way to escape before the Isle of Thom takes them to a deep and watery grave.