The unaired episode 26 of Meiken Lassie.

Shibuya, Tokyo, is bustling with the Halloween season. A wedding is being held at Shibuya Hikarie, where Sato is dressed in a wedding dress. While Conan and the other invited guests are watching, an assailant suddenly bursts in, and Takagi, who was trying to protect Sato, is injured. Takagi survived and the situation was settled, but in Sato's eyes, the image of the grim reaper that she had seen when Jinpei Matsuda, the man she had been in love with, had been killed in a series of bombings three years ago, overlapped with Takagi's. At the same time, the perpetrator of the bombings escapes from prison. Rei Furuya/Toru Amuro, a member of the public safety police, is hunting down the man who killed his classmate, but a mysterious person in disguise suddenly appears and puts a collar bomb on him. Conan visits the underground shelter where Amuro is hiding out to disarm the collar bomb, and hears about an incident three years ago when he and his now deceased classmates from the police academy encountered an unidentified virtual bomber named "Plamya" in Shibuya. As Conan and his team investigate, a disturbing shadow begins to loom over them.

"How were Gaia Memories created?" "Why did W begin to fight?" To answer Tokime's questions, Shoutarou quietly begins to tell a story. He speaks of his meeting and parting with a man he admired and called his old man—his mentor, Soukichi Narumi. Mysterious people called Dopants, who utilized the powers of Gaia Memories, had begun appearing in the shadows of Fuuto, the windy city. A young Shoutarou had become an assistant of the detective Soukichi and, though called half-baked, began to follow in his footsteps. Unaware that, in addition to his detective work, Soukichi was secretly acting as Skull, Shoutarou began to grow frustrated with his mentor. That was when the Narumi Detective Agency received a phone call—a request from Hell inviting Shoutarou and company to a fateful night! When Shoutarou tracked down Soukichi to deliver the "trump card" bestowed by the mysterious caller, what did he see? Shoutarou and Philip. The one detective made of two and the night when Kamen Rider W began. That whole story will finally be revealed. (Source: Official site, translated)