A remote island in the Seto Inland Sea. One of Japan's leading wealthy people undergoes a mysterious suspicious death, leaving behind a huge heritage. Immediately before his death, the wealthy man asked Wakamiya to search for the criminal in the attempted kidnapping of his beautiful daughter. Shishio and Wakamiya land on a closed island to find out the truth. What awaited them was a Western-style building with a strange appearance and howling dogs. The suspects are strange and splendid clan members and suspicious people who lie. Eventually, when the curse transmitted to the island is whispered, new incidents chain and disappear one by one. Wakamiya falls into a trap like a bottomless swamp. A lion who regrets solving the mystery. Was this a "Pandora's Box" that shouldn't be opened? Don't step into the mansion.