The opening ceremony for the new Twin-Tower building in Nishitamashi City is about to happen. With 75 floors, the towers seem to reach the heavens when seen from below. Conan and the others see the towers on their way to a camping trip and decide to stop by. They soon meet up with Ran, Sonoko and Kogorou coincidentally. The president of the Tokiwa Group, Tokiwa Mio, knows Kogoro from college and planned on showing him around before the public opening. While on the 75th floor, where the party is taking place, Conan overhears a couple of workers discussing an unusual car that was seen parked in front of the building: a black Porsche 356A! The same type Gin of the Black Organisation is driving. Later that night a murder happens in the building and as so often Conan will be trying to solve the puzzle of finding the culprit and getting to know what role the Organisation is playing this time.

The victim is holding a picture of Kogoro’s client – does that make her the prime suspect?! What else is the client hiding from Conan and Kogoro?

Conan, Ran, Heiji, Kazuha, and Kogoro go to the Isle of Mermaids at the request of a client.