"Detective Conan: The Scarlet Bullet" is the 24th installment in the Detective Conan film series, set within the broader universe of the long-running anime and manga franchise. The story revolves around the World Sports Games (WSG), a global sporting event held in Tokyo, which becomes the backdrop for a high-stakes mystery involving a high-speed bullet train, the WSG, and a shadowy organization. The narrative intertwines the WSG with the disappearance of prominent figures connected to the event, including a former FBI agent, leading to a complex investigation.

The plot centers on Conan Edogawa, a brilliant young detective who is actually high school detective Shinichi Kudo, transformed into a child by a mysterious poison. Conan, along with his allies, including his childhood friend Ran Mouri and her father, private detective Kogoro Mouri, becomes embroiled in the case when a WSG sponsor is kidnapped. The investigation reveals a connection to the "Scarlet Bullet," a cutting-edge magnetic levitation train capable of reaching unprecedented speeds. The train is set to debut during the WSG, but its unveiling is threatened by a series of coordinated terrorist attacks.

As Conan delves deeper, he uncovers a conspiracy tied to a criminal syndicate known as the Black Organization, the same group responsible for his transformation. The case also involves Akai Shuichi, a former FBI agent presumed dead, and his family, including his younger brother, Subaru Okiya, and sister, Masumi Sera. The narrative explores themes of family, loyalty, and the consequences of past actions, as the characters confront their personal histories while racing against time to prevent a catastrophic event.

The film features a blend of action, suspense, and intricate detective work, with Conan employing his deductive skills and advanced gadgets to unravel the mystery. The story culminates in a high-speed chase aboard the Scarlet Bullet, where Conan and his allies must thwart the terrorists' plans and save the hostages. The resolution ties together multiple plot threads, offering a satisfying conclusion while leaving room for future developments in the overarching narrative of the Detective Conan series.