The opening of a definite series.
Our hero, the youngest apprentice, is sent to do maintenance on the town clock, and run some errands, and stop by a junkyard in search of some useful junk.
What he finds is a little girl with wings. Or one wing, and a wound where the other one was.
Takes care of her, with some help from the other prentices. Reads books. Tries to make a new wing. And trouble finds them.