I'm going to start by pointing out that I have a soft spot for Sabriel, the first book in Garth Nix's Old Kingdom series. Clariel, which I just finished, is a prequel to the series and I'll get right to "reviewing" the book after I explain why I have a soft spot.
Many years ago (1997) my first novel came out and I did my first reading at Bastion Books in Nanaimo, British Columbia. When I was finished, Thora, the bookstore owner, said, "I want to give you a book as a thank you." And she handed Sabriel to me (bookstore owners seem to have an ESP when it comes to choosing the right book for the right person). I fell in love with the tone, the magic, and the ability of the author to make a new and interesting fantasy world ring with truth. So that's why I have a soft spot. I, of course, I read the following two books in the series.
Flashforward to now. Clariel, the prequel, was released almost twenty years later. I wondered if Nix could return to that world and capture the same voice. I'm pleased to say that the book rings with the same believability and authenticity as the trilogy (in other words the Old Kingdom still feels real). Clariel is a strong character with stark choices to make in her life. And the story itself does not feel as if it's a retread of the other novels. In fact it's a pleasure to see the Kingdom in its more idyllic days (uh, not that everything is rosy--far from it--there are intrigues within intrigues in the palace and, on top of that, the constant threat of free magic creatures). And it's a pleasure to have Mogget, the cat who is more than a cat, come back to life again (one of my favourite characters in fantasy fiction). All in all, a tale well told.
When I was finished, I began reading Sabriel again. The two books work well together (even though the stories take place hundreds of years apart). So if you haven't read any of this series start with Clariel. Then follow the path from there...