In Nazareth, Mary counts her blessings when her parents arrange to marry her to a local carpenter, Joseph. He has a good heart, and she grows to love him as he struggles to build them a home under her mother's watchful eye. In Bethlehem, Thomas the shepherd struggles to pay his taxes while his wife lies ill. And out in the east, the Magi gather to discuss signs in the heavens that herald a great event.

Mary is visited by the angel Gabriel, and she learns she will bear the son of God. Deeply troubled, and unable to tell Joseph of her dream, she travels to see her cousin Elisabeth, who is also mysteriously with child. Thomas the shepherd begs for more time to pay his taxes, but instead he has to watch as his animals are slaughtered before his eyes. Frustrated by the Magi Council's reluctance to investigate the celestial conjunction, Balthasar, Melchior and Gaspar resolve to set out on their own. They head west, towards Judaea.

Joseph cannot accept Mary's explanation for her pregnancy. Her neighbours turn against her, and she is in danger of being stoned. Her father, Joachim, begs Joseph to take her to Bethlehem, since he must travel there for the census. The arrival of the Magi on his borders makes Herod deeply suspicious, so he sends Nicolaus to discover the reason for their mission. The Magi, however, are wary of revealing the truth to the emissary of a king with Herod's reputation. Thomas the shepherd seeks answers for his plight. He hears of the coming of the Messiah but takes no comfort in the words.

Joseph and Mary arrive in Bethlehem but discover they are not welcome - Joseph's family know of Mary's apparent betrayal. When Mary goes into labour, Joseph searches for somewhere for her to give birth, settling on a stable behind an inn. Thomas the shepherd is driven to violence in his rage and frustration, until he learns that the talk of the coming of the Messiah is not just words. And as the stars align, Balthasar, Melchior and Gaspar hurry in disguise to Bethlehem, desperate to be present at the greatest moment in history.