Mila and her sisters live with their brother Oskar in a small forest cabin in the snow. One night, a fur-clad stranger arrives seeking shelter for himself and his men.

But by the next morning, they've gone - taking Oskar with them.

Fearful for his safety, Mila and her sisters set out to bring Oskar back - even it means going north, crossing frozen wild-lands to find a way past an eternal winter.