I was surprised by how much I enjoyed this. It's a good, solidly-written YA story which felt appropriate for young adults (even with the subtle bestiality thing). The teenagers were believable as teenagers, even with the supernatural elements. I thought the relationship between Grace and Sam was sweet. If I had read Shiver when I was twelve or thirteen, I would have loved it as much as Silver by Norma Fox Mazer, Mary Downing Hahn, or Lois Duncan. 
 Also, dude this book has a lot of virginal teenage relationship porn (you know, touching, kissing, chastely worship of one another etc.) which I would have ADORED when I was a pubescent. This sort of stuff is less magical now that I am in my late 20s and have been a house-frau for almost seven years, but I can still appreciate it. 
 I have to repeat that I LOVE the cover art and the blue typeface. It doesn't take much to please me, you see. Linger is the same except in Legolas-legging green so my delight over book design will carry over to the next book.