Libelle, a city by the sea. All who venture into its fog are said to never make it back alive-a murderous phenomenon that's another one of the four great calamities that completely ravaged the world. And it might be the solution to Menou's problem. To fulfill her role as Executioner, she still needs to find a way to murder Akari, the girl who seems to spring back to life whenever she's killed. Maybe this time, Menou will be successful in carrying out her duty...