After receiving a death threat, the young violinist Mari Sakurai will remain isolated along with the rest of the finalists of a prestigious musical contest in a residence on the outskirts of Tokyo. Detective Katayama is chosen to protect the participants. During the week they will be incommunicado, Katayama, along with the insightful cat Holmes, will face countless unexpected events and unveil the darkness behind the scenes of the brilliant music scene. A prestigious violin contest. Seven finalists A death threat A residence on the outskirts of Tokyo. A spiral of crimes ... The return of Gata Holmes, one of the most popular and beloved characters in Japanese fiction.