The Relic Master: Book Of The Crow 1 by Catherine Fisher
Raffi is apprenticed to the Relic Master, Galen, whose task is to keep safe the relics of a bygone age. But his powers are weakening and he and Raffi set off to meet the Makers in the City of the Crows and discover why. The journey is beset with dangers and Raffi's courage is tested at every turn. They are joined by the enigmatic girl Carys and face an uncertain future in the City of Destruction. Will they be able to summon the Crow to help them? Or will the everpresent Watch eventually eliminate them?