Conan Edogawa and his classmates are assigned to do a class report about a small business of their choice. After discarding other possible topics, the Detective Boys concludes that it's a perfect opportunity to find out more about Detective Kogorou Mouri's job.

Conan's friends refuse to settle for a simple interview though, as they want to experience first-hand all the details of his work. Thus, they, along with a reluctant Conan and Ai Haibara, decide to tail the renowned detective for a day. However, the kids soon get involved in a grim situation when Kogorou's current case takes an unexpected and dangerous turn.

Conan tries to figure out the phone number to the boss of the Black Organization. Mouri is invited by a granddaughter of a rich household to solve these mysterious accidents that happen whenever someone tries to play a Stradivarius for her grandfather on his birthday. Four incidents have happened on that day already and it is about to come up again. Later a fire occurs and a man is burned to death.