Itogami Island is abuzz with preparations for the Halloween festival, and who should be visiting for the occasion but Kojou Akatsuki's friend from elementary school, a girl named Yuuma Tokoyogi.
But as Kojou reunites with his friend, his homeroom teacher, Natsuki Minamiya, goes missing!
Meanwhile, a strange space-time distortion is turning the sanctuary of Itogami Island into a labyrinth from which escape is impossible. And what's behind the physical changes that come over Kojou whenever he has physical contact with Yuuma?
The long-awaited fourth volume of the light novel series is here!