(I'm posting here because I coun't find the 4th book)
This book continues the story and plot really well connecting the last book and maybe the next book. In this book we get to see a lot more of phony bone and near the middle and end we get to see the leaf bug again. This books basic info(small spoilers) is we learn more about thorn being a princess, the protectors of the great red dragon, a war starts, and many new things happen in the village.