I've been meaning to comment on this, since I mentioned rereading it and wondering if it would be as good the second time around. Well, it was.
This is one of those books that you start out reading, you're a bit confused, you take your time with the first fifty pages or so, trying to sort out who's who and what's going on. This was especially true for me, since a great deal of the book's power is in the emphasis on Maori culture, which I am woefully ignorant of. Then you really get into it and you start reading obsessively, desperate to find out What's Going to Happen. And then It happens, and you get depressed, and don't want to read anymore, except that you've started to fall in love with this characters, and you need to know how they get themselves out of this situation. And so you finish it.
Most of it is very good, well-written, excellent characterization and descriptive writing that makes you feel as if you are in New Zealand. The plot is fairly good--a couple of odd twists, but hey, what do I know of the cultural norms in an isolated town in New Zealand (see above, re: Maori culture)? However, the ending is a bit too pat, and while it's emotionally satisfying, it's artistically disappointing.
That said, however, find it and read it anyway. Powerful reading for a snowy weekend. Bet you'll find yourself Googling for Maori info before the weekend's over!