Ever since Grace was almost killed by wolves as a child, she has been obsessed with the one wolf that saved her. She considers that wolf to be her wolf. Little does she know that the wolf is actually a werewolf named Sam whose shifting is controlled by the temperature—he's a human during the summer, but forced to be a wolf during the winter. And Sam is just as obsessed with Grace as she is with him.
Despite having read this about a month ago, before reading a plot summary, the only thing I could remember of the story was that Grace was so in love with a wolf that humans just didn't interest her anymore. She doesn't even find out that he can turn into a human until later in the book. And she puts her wolf above everyone else, which results in her being a pretty terrible friend.
I think the reason I forgot almost everything about the book is the fact that I was bored even while reading it. I didn't connect with the characters, and the plot didn't interest me. The most memorable aspect of the book for me is the near bestiality with Grace's obsession with a wolf.