Yoshimori s absentee mother, Sumiko, makes an unexpected appearance at Karasumori but not for a tearful family reunion. Sumiko leads Yoshimori and Tokine through a labyrinth to find and remove the mystical site s mysterious guardian ... What does Sumiko know of the circumstances surrounding Tokine s father s death? Can she be trusted? Can Karasumori s guardian be trusted...? And what fate awaits Karasumori if its guardian leaves?!