Halna, a nurse at the Celgel Falls General Hospital, has her world crumble around her after one fateful stampede. With nothing left for her in her home, she enrolls in the exchange program. Meeting Lachlan, a UN transport pilot, the two become quick friends. At the onset of the war, both make a decision they will come to regret. The planet Cocytus lies before them, a siren lying in wait. Will they survive their descent into hell? Or will they be consumed by the fear of the cold?