Makoto and Megumi goes on a high school graduation trip.
Due to an accident, they instead find themselves at the mansion deep in the mountains,
spending the night with a group that has been invited for mystery party.

However...
What these two encounter is a terrifying murder.
What does a series of tragedies indicate?
Can they solve the case and return alive safely?

A visual novel that describes a night of terror.

[Translated from official website]