Hanna learns via email about the death of her best childhood friend, Fido. The news reaches the glaciologist during a crucial expedition to Antarctica. Since Fido disappeared without explanation twenty years ago, Hanna has tried to banish the once-familiar figure from her mind. But now, in the endless expanse of ice, memories and unresolved questions come rushing back, and Hanna loses control. As tensions rise within the research team and a snowstorm threatens the success of their project, time in the ice ultimately becomes a test of endurance.