When experienced ski patroller Greta Westerlind awakes in hospital having almost been killed in an avalanche, she is devastated to learn that her close friend, bond trader Warren McGovern, perished in the slide. With no memory of the incident, Greta is at a loss to explain why the two of them were skiing in such lethal terrain in the first place. As she struggles to unlock her memories as to what really happened that day, a series of strange and menacing incidents convinces Greta that someone means to harm her. Then a young woman disappears, and events take a terrifying new twist ...