In a post-apocalyptic ice age, neomage Thorn St. Croix was nearly driven insane by her powers. She lived as a fugitive, disguised as a human, channeling her gifts for war into stone-magery. When she was discovered, her friends and neighbors accepted her, but warily. Not so the mage who arrives from the Council of Seraphs, who could be her greatest ally-or her most dangerous foe. And when her long-gone sister, Rose, is revealed to still be alive, Thorn must make a choice-and risk her own life in the process.