Our hero Kes is an autistic waif of a girl. Well, actually, I'll let the author tell it: "She has some skill with herbs, and she can stitch a cut or set a bone. A man came and asked her to come, and she went up into the desert to help somebody who'd been hurt. Before we even knew there was a desert."
...which choice launches us nicely into the plot--and gratifyingly, that happens in the first chapter so things start moving pretty quickly. There's a shift to a second set of characters in the second chapter, and though that one's a bit of a snoozer we're back with Kes in chapter three and the alternation is established. That third chapter picks up the pace again and thereafter there's always a battle or some other appropriate tension in play. The plot is well accomplished if not particularly twisty, and the griffins themselves bring a refreshing mindset to the field.
The author has, though, done herself a disservice by choosing a shy, tentative girl as the MC; she keeps that identity a little too long and the MC gets a little mired in self-pitying whining from time to time. Ultimately she does show the inevitable character growth everyone had expected, but when all is said and done the MC has not become a strong personality (the obvious choice for growth), but rather an aloof one. That particular progression rang a little hollow; who wants an aloof main character?
In all I found the author pulled off a good balance with this book: the characters were distinctive without being too stereotypical, the environment was conveyed well (desert scenes play strongly here) and after that one misstep with chapter two the pacing never really sagged. The last of the plot pieces ended satisfyingly, leaving enough unsaid to lay the foundation for a sequel. I didn't find anything in here particularly compelling--which is to say it's not of the same caliber as such books as The Name of the Wind or The Blade Itself--but it's a fine first offering and I'm pleased to see there's a whole trilogy waiting.