Book the most recent in an involved series. OK, I went into the other room to check; it's Book 5 (and last) of the Alliance of Light Series, but before that there were three books (starting with "Curse of the Mistwraith") in the "Wars of Light and Shadows" series, and things carry on fairly seamlessly through all eight books. (Seven in the US, I think, but my 2 and 3 were the UK editions, which came out separately.) The series has had a checkered publishing history; the book before this was published (late, with sub-par graphics) by the ill-fated Meisha Merlin, and this one didn't get a US publisher at all.
Wurts's prose has always been idiosyncratic; my usual comment on it as that no noun is left without its duly sanctioned adjective. Or alternatively, that the books would be a great deal shorter if she could confine herself to one adjective per noun. Also, she has a habit of using "if" where most writers would have "though." All that makes the reading go rather slowly, and it seems to have grown denser and more opaque over the years, as well as developing an infestation of random italics.
( What it's about. )