I've read ALL of Mercedes Lackey's Valedemar series, and she's running seriously short of ideas.
I bought this book because I was interested--the others were decent and fairly interesting, and so I thought I'd try this one. I now think it should stand as the classic example of why authors shouldn't make serieses run on too long.
This book is four hundred and twenty-eight pages long, and everything that happens could be contained in about ten. We struggle through Karal feeling lost and lonely, An'desha feeling put upon and self-pitying, and everyone realizing that magic isn't the answer to everything. It gets so repetitive at the end that I was extremely tempted to just shove it in a corner of my bookshelf with the other two books in the series and not finish any of them, and I almost ALWAYS finish books, unless they're ghastly. This one came pretty close.
If you want to start out with Mercedes Lackey's Valdemar series, read The Heralds of Valdemar (ARROWS OF THE QUEEN, ARROW'S FLIGHT, ARROW'S FALL) and Vows and Honor (THE OATHBOUND, OATHBREAKERS, OATHBLOOD) first. If you've read all her Valdemar books, read this just to fill in on what happens, but don't waste your money buying it.