In the aftermath of the Queerats' sneak attack, Saki and Satoru join three others (Okano, Kuramochi and Satoru) to form a new group of five to visit the hospital and check on one of their injured friends. As they arrive, they find the hospital damaged. They clear the place of armed Queerats and rescue the few human survivors, but the party is attacked by an unknown individual who kills everyone in their path with an overwhelming power. Fearing that the enemy in question may be a Fiend, the other members of the party decide to sacrifice themselves to let Saki and Satoru to escape and warn the others. However, as their boat floats down the river, the duo realize that they are being followed by the enemy.