I read this book with the full knowledge that I was doing something I try not to do: reading a series out of order. But my logic was as follows: 1) they didn't send me the first book in the series; 2) the library doesn't have it; 3) I don't want to go out and buy and read a book just to read another book when I don't even know if I'll like either one; 4) it's a YA, and a lot of kids end up reading series out of order because of the vagaries of the library system, their aunts and uncles' gift-giving tendencies, or whatever. So reading this one out of order is not inappropriate for what it is.
This is extremely thoroughly the second book of a trilogy, not a stand-alone work. And yet I got caught up remarkably quickly--interesting, since I started another second book right after finishing it, how much more utilitarian children's/YA authors are willing to be at the "these are the characters and what they've been up to" part--although it probably helps that this is the "character as role" version of YA adventure characterization, with one character as The Comic Relief, another as The Soul Of Honor, etc.
That sounds lukewarm, and in fact it's not. I liked this book, and not just because it was filled with Inuit spirits and Arctic animals. (Although I am easily bought that way.) I've gone and added the first one to my list even though it sounds like it's set completely away from happy snowy things. It's an alternate history that is not fixated on all the historical figures coming out the same way as they do in our universe or making cameos; it's a completely syncretist approach to mythology, but in a way that's more selective than just sticking stories in a blender and pressing a button. This is very middle-book, so the characters' struggles are not completely resolved, but they do struggle, and they care about each other, sometimes in difficult ways, and there are lots of fun bits of imagery.
Possibly I am just a sucker for giant shapeshifting polar bears.