The Night Beyond The Tricornered Window Vol. 3

In Vol. 3, a group of people have suddenly gone missing for no apparent reason. Though they were all seen in the exact same place, the disappearances aren’t related to each other, and there doesn’t seem to be a connection to the place either. Detective Hanzawa is stuck in his investigation and asks Rihito for help, but is he walking into a trap?
Notice: This book is written in Japanese.