The episode begins with Ran, Sonoko, and Conan visiting an exhibition of the imperial treasures of Robanov, which includes the Queen's Bang, a diadem adorned with a large garnet. The exhibition has drawn a large crowd, as the notorious thief Kaito Kid has announced his intention to steal the diadem.

At the exhibition, they meet Azusa and Amuro from Café Poirot. To avoid drawing attention, Azusa suggests accompanying Ran and Sonoko, while Amuro goes with Conan. The group discusses Kaito Kid's announcement and his reputation as the "Magician of the Reiwa Era."

Amuro performs a card trick for the group, which is interrupted by a mysterious man who demonstrates a more refined version of the trick, where the cards transform into doves. Conan suspects that the man is Kaito Kid in disguise.

Inspector Nakamori and public security officers, including Amuro and Kazami, discuss the security measures for the exhibition. They are concerned about the upcoming visit of Queen Elizabeth and the potential theft of the "Bang of the Queen." Suzuki Jirokichi, the exhibition's sponsor, reveals a trap designed to catch Kid if he attempts to steal the diadem.

Shortly before midnight, the time Kid announced he would steal the diadem, the room fills with white mist rising from the vents. The mist is identified as white spray paint, obscuring everyone's vision. Amuro and Kazami, wearing gas masks, remain in the room while the others are evacuated.

When the mist clears, the diadem appears to be missing, and a card from Kaito Kid claiming the theft is found. However, Conan suspects that Kid left the card as a diversion and did not actually steal the diadem.

Azusa, who had left earlier, returns to the exhibition room and claims to be a fan of Kaito Kid. She suggests that Conan, a child, inspect the diadem's display case to confirm the theft, as Kid cannot disguise himself as a child. When Conan opens the display case, he finds the diadem missing.

Inspector Nakamori orders a search of the entire building, believing Kid is still inside. Conan analyzes the situation and concludes that Kid could only have disguised himself as one of three people who were not wearing gas masks during the theft.

The episode ends with Conan realizing the true nature of Kid's plan and preparing to confront him in the next episode, setting the stage for a showdown between Kid and Amuro.