A lazy drive through the country lands Kogoro, Ran, and Conan in the middle of a murder mystery surrounding the death of billionaire industrialist, Kosaku Hotta. As Conan tries to unravel the clues before the killer can strike again, he faces one disturbing reality: The prime suspects are the victim's children?! It's an explosive whodunit you won't want to miss!
The killer was... none of the Hottas. It was Yamauchi, whose son was a deceased piano player. When he and Fumiko got in a relationship and Hotta Sr. objected, they tried to convince him otherwise, but in reply Hotta broke the younger Yamauchi's hand which left him unable to play anymore. The younger Yamauchi fell into despair and killed himself by driving into a nearby cliff. His father then became the family butler only to get revenge, preparing the bomb that killed Hotta Sr..
Yamauchi had also planned to kill Fumiko by tampering with her car, mistakenly thinking that she had rejected his son after the incident. In reality, Fumiko was very traumatised as well: she showed it by dressing in black like a widow and wearing a pendant with a photo of her lost love. Fortunately, Yamauchi's trap failed and she returned to the mansion, making Yamauchi break down in tears for misjudging her.
