The Suzuki Corporation holds a hot balloon competition, and Sonoko, Ran, and Conan take part in it. During the race, the reigning champion Shingo Mizuguchi's balloon collides with Akihiro Okuda's and begins falling. As the balloon descends, his wife, Arisa Mizuguchi, falls to her death. Because Mizuguchi and Okuda fought before the race, the police suspect Okuda deliberately crashed into Mizuguchi's balloon. Okuda insists it was an accident but based on the condition of Okuda's balloon, Conan determines it was not an accident but a murder.
