Julie, a stage actress, plans to use her star sapphire for an upcoming production and seeks Kogoro Mouri to help guard it after presenting him with a letter from Kaito Kid, who arrives at the theatre dressed as Shinichi Kudou.
On the night of the theft, Kid appears at the theatre in disguise as Shinichi Kudou but ends up fleeing with the jewel, leaving the audience and performers buzzing with disbelief.
To show thanks, Julie invites Kogoro and the rest of the group to Hakodate, and they set off on an airplane to reach the city by the sea.
In the air, one of the show’s actors, Isao Shinjou, who was supposed to be elsewhere, joins the flight along with Ran's mother, Eri Kisaki, creating a tense, traveling mystery among familiar faces.
As the plane takes off, Julie comes into contact with most of the people she invited, turning a celebratory trip into a tangled web of suspects in her death.
The investigation unfolds quickly, with Eri Kisaki working to uncover the truth, and the culprit is revealed as Natsuki Sakai, the makeup artist, whose presence on board raises the stakes and deepens the intrigue.
With the flight crew poisoned, Shinjo takes over the controls and appoints Conan to assist, setting the stage for a clever cat-and-mouse dynamic at 30,000 feet.
Conan soon realizes that Shinjo is actually Kaito Kid when pressed to help, and Kid confides that he is no longer pursuing the sapphire after discovering that it is a fake.
A raging storm and a small airport fire threaten a landing while fuel runs low, prompting Conan to guide the plane toward a stable area that can support a safe landing.
Ran Mouri and Sonoko Suzuki eventually take over piloting duties, while Kid escapes by leaping from the plane, and Conan switches to Shinichi’s voice to guide Ran through the approach and touchdown, keeping the stakes high until the very end.
During the flight, Ran remarks that Shinichi is like an eclipse—one moment he’s there, the next moment he isn’t—a line that captures the fragile balance between danger and safety up in the air.
When the plane finally lands, Ran tells Shinichi that she loves him, only to notice lights at the site that hint at a larger, ever-present tension she must face.
It turns out Kid steered toward a police station, using police cars as guiding lights to land, and the culprit is finally brought to justice while Ran and Sonoko receive medical attention from a medic on site.
In the post-credits scene, the medic is revealed to be Kid, who commends Ran for landing the plane safely before vanishing, leaving Ran to resume a phone chat with Shinichi and quietly hope that her secret remains safe.
