The long, cold winter in Alaska does not bode well. Caught in a snowstorm, inventor Lisa McCall disappears without a trace. Leaving everything behind, her older sister Abby flies from England to join the rescue efforts. She has not spoken to her sister for four years after a terrible quarrel, and now it suddenly becomes clear that they may never have a chance to make peace. Alone in the frozen lodge, dealing with her own personal drama, Abby struggles to understand how and why Lisa disappeared. And he soon realizes that everything is much worse than it seems. But if she wants to survive, she will have to get to the bottom of the truth.