Book excerpt: When Gerta's friend Kay is stolen away by the mysterious Snow Queen, it's up to Gerta to find him. Her journey will take her through a dangerous land of snow and witchcraft, accompanied only by a bandit and a talking raven. Can she win her friend's release, or will following her heart take her to unexpected places? A strange, sly retelling of Hans Christian Andersen's "Snow Queen," by T. Kingfisher, author of "Bryony and Roses" and "The Seventh Bride."