Ice is the best paranormal romance I have read this year. I can count the number of PNR novels I've read on one hand the last twelve months, so that recommendation alone might be not enough to convince you how good this book is. So let me persuade you.
In a word, Ice is lovely. Sarah Beth Durst's descriptions of the Arctic are detailed and transporting. It's unusual for a YA book to be set in such a locale and I appreciated the change of setting. Cassie herself is a pleasure. She becomes caught between two worlds: the future she's envisaged for herself, and the one she's destined for because of the promises of her parents and the capriciousness of magical creatures. Because Cassie is an older teen, Durst was able to grant her much of the decision making and tackle obstacles on her own. I enjoyed very much watching her and Bear fall in love. As Cassie could never look upon his face the reasons for their love were for more complex than "because he is handsome".
Ice is based on the Scandanavian fairy tale East of the Sun, West of the Moon. It departs from the original tale in several places, but Durst has kept the "fairyness" of fairy tales in her story. Cassie, full of questions, is told by Bear that she must stay one day in his castle for every question she asks; she must never look upon his face and never know the reason why; verbal promises are binding. There's also a very modern aspect to the story. Cassie struggles to find a way to fit a husband and children plus her passion for science into an increasingly complicated life.
Ice is that rare creature: a fulfilling romance. The dedication at the beginning is sweet enough to bring tears to your eyes once you have read this tale:
For my husband, Adam, with love. I would go east of the sun and west of the moon for you.