Erik Amdahl and his spirited daughter, Sofia, have embarked on a long-promised cross-country ski trip deep into Norway's arctic circle. For Erik, it's the chance to bond properly with his remaining daughter following a tragic accident. For Sofia, it's the proof she needs that her father does care. Then, far from home in this snowbound wilderness, with night falling and the mercury plummeting, an accident sends them in search of help - and shelter. Nearby is the home of a couple - members of Norway's indigenous Sami people - who they've met before, and who welcome them in. Erik is relieved. He believes the worst is over. He thinks that Sofia is now safe. He could not be more wrong. He and Sofia are not the old couple's only visitors that night - and soon he and Sofia will be running for their lives - and beneath the swirling light show of the Northern Lights, a desperate fight ensues.