A scientist, an atheist, of some possible future when atheism is nearly universal, travels back in time and finds that his craft is taken for the star in the East. He realizes that although he is no infant, he is the historical figure upon which the biblical Jesus is based.

He considers that his very future existence depends on the action of the Christian faith over thousands of years, regardless of his own understanding. If this faith goes unrealized, his entire family tree will be regrown in patterns which create some other man. To live, he must present a Jesus to these assembled shepherds and other followers. In his Jesus must be found the heart of Christianity.

Panicked, searching his brain for information about Jesus, he comes up with scraps of miracles and parables. In no way able to turn water into wine, he is at a loss even to picture a mustard seed, much less find truth in it. He grows depressed.

The disciples worry for him, but don't waver in their faith, surprising the scientist. Yet, he is certain they will waver. He knows he can never perform a miracle. As he doubts, his intellect founders, drawing him deeper into despondency. He does not fear for the world without Christ, but for himself without History.

In a strange room, dark with night, reaching for a light switch but feeling only the splinters of an unfinished wall, one can only sit down quietly and wait for sunrise. Hopeless, he stops being Jesus Christ. He is just Jesus, a man building a meager woodworker's life in Galilee.

Yet still his friends follow him. He peers in their eyes and sees wells of pure water cut into solid earth. Their faith in him grows ever stronger, even as his woodworking turns out barely better than his miracle-working. One or two may well even detest him, but yet they remain.

He takes their faith as his model. These disciples, as aware as he of his undoing of prophecy, beckon him not from an observation point, but from the thick of life. His failure, an immeasurable disaster on his terms, is to them a mere blemish on the sphere of divinity.

In this realization he becomes Son of God, and the story ends with this resurrection of faith in the faithless.