Corey and her best friend, Kyra, are inseparable. Corey is the only person who understands Kyra's high-highs and low-lows. So when Corey's family moves away from their Alaskan town, she makes Kyra promise to stay strong during the long, dark winters and wait for her return. Except Kyra doesn't. Two days before Corey is to visit, Kyra is found floating underneath the ice.