Steven is a visitor from Ormingat, living on earth with his family for a designated number of years. When his earthly son Jacob is born with a fatal immune deficiency, Steven requests help from Ormingat to save his life. The boy survives but grows up surrounded by a protective shield unable to make friends. When Steven is forced to tell Jacob of his identity, Jacob resents his father`s imposition. Then there is the debacle of the Derwents’ accident and Nesta`s flight from home, bringing dangerous publicity to the Ormingat aliens. Steven, summoned to return early to the mother planet is reluctant to abandon Jacob and his earth wife, Lydia.