Fletcher, Susan. 2006. Alphabet of Dreams.
Set in the Ancient MiddleEast (Persia/Babylon/Judea), Mitra and her brother Babak are beggars who are not what they appear to be: royal children on the run hiding from an evil king who murdered their parents. They have escaped notice from the adults so far, but when Babak starts having "true" dreams about other people, attention begins to fall on them. In some ways, they are better off than before. They now can pay for food instead of steal it, but in some ways it is dangerous for people are talking about these strange foreigners who have dreams that foretell the future. When Babak is 'captured' by a/the magus (magi), he begins dreaming of stars, kings, and a newborn baby. Mitra and Babak travel with the three magi on a long journey that ends in Bethlehem.