Living in a small village, Megumi's two main interests are classmate Natsuno Yuuki and a European-style house on a hill. One day, when her fascination with the house leads her to climb the hill, she vanishes.
As the death toll rises, Toshio and his staff gather to further examine the fatal sickness plaguing the isolated town. Seishin's eerie admirer returns with an observation that makes her oddly wise for her age.
After visiting the surviving families of the deceased, Seishin discovers a peculiar similarity amongst every victim. Natsuno is tortured by helplessness as his visions of Megumi become terrifyingly close to reality.
It's clear to Toshio that the source of the deadly illness won't be found using conventional methods. He and Seishin observe a patient overnight to catch any sudden changes in her condition--or possible moonlight visitors.