So for the Emelan series, I have only read the Circle of Magic quartet, which this is the third of. For whatever reason, Daja's Book was also the one I remembered the most and it's as great as I remember.
The four students and their teachers go with Sandry's uncle as he inspects the northern area of their country, Gold Ridge Valley. Daja is a former trader who was cast out of the Trader clan when she was the lone survivor of a shipwreck. In their lore, she was now untouchable, trangshi. While she helps out in the blacksmith with her metal and fire abilities, a trader stops by to buy some materials. Because the four young mages have been having issues with their powers since they combined their abilities in the first book, Daja suddenly finds herself creating a living metal tree. One which the traders want to buy, but to do so Daja insists that they negotiate with her.
At the same time, the group discovers that this mountain town has not had any fires in many years due to a mage who stops them as soon as they begin. A drought resulting in a dry region and years since a fire to clear out all the brush are a bad combination.
Another great book and one that stuck with me for over 10 years.