Many years in the future when the Earth has become too polluted to support life, Noah and his family build a space ark and take the animals and plants that are still surviving to search for a new home.
During the long, arduous voyage of the ark, Noah discovers that the sheep's wool has become matted into a strange material, for which he finds a practical use once the ark has come to rest atop a mountain.
The fifteen-year-old Murry twins, Sandy and Dennys, are accidentally sent back to a strange Biblical time period, in which mythical beasts roam the desert and a man named Noah is building a boat in preparation for a great flood.