After a climate catastrophe, the world has turned into a sea of ​​ice. Few people survived and retreated to cities surrounded by great walls. Night after night they have to defend themselves against attacks from icy and very dangerous monsters. The young Sami lives in one of the human settlements and has a big dream: he wants to become part of the city guard and protect his fellow human beings from the ice monsters. But then he is injured during an attack and his body transforms into a being half human, half monster...