Otto Tattercoat and the Forest of Lost Things

"In the city of Hodorf, the Tattercoats live by a strict code. Only steal what you need, don't leave a trace of yourself behind, and if another Tattercoat is in trouble, you must always help them out. These are the rules that guide Nim's life as she and her rat, Nibbles, live on the streets and the rooftops of the only place she's ever called home. So when a new boy named Otto comes to town and gets caught up in the devious plottings of a former Tattercoat who's fallen from grace, Nim takes it upon herself to come to Otto's rescue"--