I'll confess that I read Melting Stones several weeks ago and then returned it to the library, so my review may be a little non-specific.
Residents on one of the islands south of Emelan have sent a call for help to Winding Circle temple: Their plants and trees and the animals that live around them are mysteriously dying. From Winding Circle come two familiar figures: prickly green mage Rosethorn, whose plant magic will help her decipher what's ailing the plant life, and Briar's former student, the stone mage Evvy. With them comes the eager, nervous Dedicate Initiate Myrrhflower and Luvo, a being best described as a walking, intelligent rock. All are pulled into the island's mystery when Evvy is caught up by the wild spirits loose in an immense bubble of molten rock. Can they evacuate the island in time--or will they try to shift a volcano?A housekeeping note to begin with: when I wrote my Tamora Pierce wrap-up I thought that Melting Stones was a stand-alone book in Pierce's Circle universe. I think it may actually be a sequel to Street Magic (The Circle Opens, Book 2) or Will Of The Empress, neither of which I've read. So there were a fair number of references to people and events I knew nothing about. I didn't have any trouble following along, though.
While I found Melting Stones to be an enjoyable book, I did find it to be a little young - while it is classified as Young Adult, I think that Middle Grade readers may enjoy it more than a teenager used to the advanced themes present in much of today's YA. Part of that is that Evvy, the main character, felt very young to me, despite the awful circumstances she's lived through.
In general, I think that fans of Pierce's previous Circle books will enjoy Melting Stones, but that it probably isn't strong enough to pull new readers (particularly new older and adult readers) into the series.
Buy Melting Stones in paperback on Amazon now.