One thing I've always loved about Wellington's books is that he never has a scientific answer for a supernatural horror. The zombies in his Monster Island series weren't caused by a virus; his vampires and werewolves don't suffer from strains of super-rabies. Instead, he allows for dark magic and curses to exist as the roots of the evil, and that in turn lets him treat these iconic creatures in original and creative ways (c.f., the awesome wizard-like liches in the Monster Island series).
Frostbite is no different. Here, the werewolves are extinct dire wolves, not timber wolves, and through the ancient curse that created them, they instinctually hate everything human, including their other halves. The story follows Cheyenne Clark as she searches through the frozen Canadian north for the werewolf who killed her father when she was twelve. Unfortunately, Chey is mauled by the werewolf and becomes one herself, forcing her to befriend her father's killer in order to learn how to survive. Of course, the killer in his human form, Monty, turns out to be a lot more complicated and, well, human than she expected. So does Monty's truck driving, inhuman, animal spirit friend, Dzo--a nice Wellingtonian touch.
It's a short novel that reads quickly, and as such parts of it felt rushed (in particular, I wanted a little more face time with the werewolf hunters during the climax). But it's a solid novel too, and as an adventure story it stands alone well even as it sets up the second book in the duology. It's also more character-driven than Wellington's usual plot-heavy novels, which shows a nice evolution of the author's style.
As a side note for Wellington fans, Bannerman Clark from the Monster Island series appears here too, as Chey's uncle, indicating that the Monster Island books take place in an alternate universe of Wellington's werewolf (and presumably vampire) series. What can I say, book nerds like me love that stuff.