The story takes place in the bustling streets of Shibuya, Tokyo, during the Halloween season, a time when the city is filled with costumed revelers and festive chaos. The central conflict revolves around a series of bombings linked to a mysterious former police officer named Furuya Rei, who is also known by his alias Toru Amuro. Three years prior, Furuya was involved in a case with his police academy comrades, including Jinpei Matsuda, Kenji Hagiwara, Wataru Date, and Hiromitsu Morofushi, during a criminal hunt for a bomber who wore a pumpkin mask. That operation ended in tragedy when Matsuda was killed by a bomb, an event that has haunted Furuya ever since. In the present day, a new wave of attacks begins, seemingly connected to the same culprit, and Furuya finds himself targeted by a mysterious figure dressed as a witch, who appears to be seeking revenge against him. The witch is later revealed to be a woman named Elenka, a former civilian involved in the past incident who blames Furuya for the death of someone she loved. As the bombings escalate, Furuya is severely injured in an explosion and is hospitalized, leaving the investigation to be taken up by Conan Edogawa, the young detective trapped in a child's body. Conan works alongside the Metropolitan Police Department, including Inspector Juuzo Megure and Detective Miwako Sato, as well as Furuya's colleagues from the Public Security Bureau. The narrative unfolds over a single tense Halloween night, with Conan racing against time to decipher the bomber's true identity and prevent a catastrophic attack on a massive parade in Shibuya. A key narrative arc involves the deepening of the relationship between Furuya and his former academy friends, whose memories are explored through flashbacks, revealing their camaraderie, their shared dreams of justice, and the personal sacrifices they made. The case also forces Furuya to confront his unresolved guilt and his complex loyalties, as he operates as a triple agent, working for the Japanese police, the Black Organization, and the National Police Agency. Conan's deductive skills are pushed to their limit as he pieces together clues from the past, including a hidden message left by Matsuda, and uses his advanced gadgets from Professor Hiroshi Agase to track the bomber. The climax takes place during the Halloween parade, where the bomber plans to detonate a massive explosive device. Conan and Furuya, despite his injuries, manage to corner the culprit, leading to a final confrontation that reveals the true motivation behind the attacks: a twisted sense of justice born from grief and a desire to make Furuya experience the same loss he once inflicted. The story concludes with the bomber's defeat, but not without leaving a lingering sense of melancholy, as Furuya mourns his fallen friends once more, and the Halloween festivities resume, the dark events of the night overshadowed by the city's relentless celebration.