Promise of Death: Detective Suguro is enjoying a stay at a luxurious hotel in Wakayama. Also staying at the hotel is an unusual family led by rich widow Mrs. Hondo. She acts like a tyrant around her children, who are afraid of her and are at her beck and call. Unfortunately, a tragedy strikes the Hondo Family while on a hike to a local shrine. Mrs. Hondo, who was supposed to be taking a rest on the way, is found dead. Kawahara Daisaku, the chief of the local police station, asks Suguro to help with the investigation of Mrs. Hondo’s death.