The Gimlet Eye — James Roy

Things are different in the sky-city of Quentaris. Since the assassination of the old Archon, the city has fallen into the hands of a lazy, power-hungry ruler who cares nothing for his people â€" only the acquisition of new and better sources of authority and wealth.
Tab used to be an apprentice magician, back in the good old days. Now she mucks out stalls and tries to duck her boss's bad temper. But she hasn't forgotten her training, and practises on her own late at night. Little does she know that her talents â€" unrecognised in the new regime â€" will take her and her friends on an adventure they won't soon forget.