Tom Nelson, a retired and embittered former school teacher rear ends a man just arriving from Utah on the San Diego Freeway and accepts responsibility for the accident, offering to pay the medical bills when the man is sent to a hospital with a broken leg, promises another car, takes care of the man's carpenter tools, and offers the young man a place to stay when he recovers, even though he has some serious doubts about the man's sanity. His doubts begin when the man identifies himself as Joshua Josephson, born 32 years ago in Bethlehem, PA. on the 25th of December, occupation carpenter and mason. They continue growing when a frantic hospital administrator pleads with him to take the young man home because of what he has been doing in the hospital, namely wandering around the corridors in crutches, healing dozens of patients, including some given up as terminal by their doctors.
He then begins a series of incredible adventures, some with strong biblical parallels, wondering all the while whether this young man is a con-man or a lunatic quack or, if he is the resurrected Christ, living as a mortal man in these modern days.