Exiled from their home country because of their father's plot against King Phraates, fourteen-year-old Mitra and five-year-old Babak, who are of royal descent, live as beggars until it is discovered that the boy can tell the future through his dreams, and the magus Melchoir and two other Zoroastrian priests take the children with them to Bethlehem to witness the coming of a new king.
