The story is set in the future in the year 2156, a time when the earth's population has grown and, although most of our current social problems have been solved, new ones have emerged. ITP stands for Interdimensional Transport Protocol, which has been developed by Dr. Deborah Tennyson to open up the universe to exploration by man. The book follows the events around the first manned ITP flight which goes awry and lands the pilot, Major David Sanders on another world, but in a Garden of Eden where man never suffered the fall. the plot follows the events around this flight as Dr. Tennyson tried to find a way to rescue Major Sanders, while he deals with the people of Eden.