A new girl named Ai Haibara joins Conan's class. She eventually reveals her true identity as Shiho Miyano (codenamed Sherry ), the scientist who created the APTX 4869 poison that shrunk Shinichi.
Knowing this will help me give you more specific details about the culprit or the clues! Detective Conan Rewatch: Episode 136-137 Stai guardando DetectiveConan Ep 136-139 ITA
Dr. Agasa takes the Junior Detective League camping, but they get lost and seek shelter in a massive, eerie blue castle. A new girl named Ai Haibara joins Conan's class
The arc concludes with Conan, Ai, and Professor Agasa attempting to recover data on the APTX 4869 from a floppy disk, only for the "Night Baron" virus to delete everything before they can read it. Case 2: The Old Blue Castle Investigation Stai guardando DetectiveConan Ep 136-139 ITA