Bangnum is a village infected with a deadly experimental virus conceived by an organization known as Blue Ship. The village is investigated by F, who discovers a young boy in the village that is unaffected by the virus.
The village is ultimately blown up to prevent the spread of infection. F manages to escape with the boy, who he sends ahead, ordering him to send a message to Watari. F dies shortly after, leaving the young boy as the sole survivor of the village.