Strike The Blood Light Novel Volume 04

"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?"