When the contraption that was used to kill the victim is found, the falling chimney incident at the resort area Conan, Ran, and Kogoro were visiting is investigated as a homicide. Several of the victim's acquaintances are staying nearby, so they go to question them. The victim's wife, the company's president and CEO, an old friend and shareholder, an investor with whom the victim had a rocky relationship, and the victim's mistress are all suspects. They discover one of the suspects is rather knowledgeable about the type of device found at the villa and becomes the prime suspect, but...