While the Detective Boys going home at the professor Agasa's house they met a new stranger. Also, Inspector Shiratori, Detective Takagi and Detective Sato are on a stakeout. The girl seems familiar at the 3 officers. Maybe she was a detective like them. Conan keeps suspecting the girl stranger until a new threat happened. The man codenamed 'Napoleon' attacking officers to silent them without knowing his real identity. Will they found out whose this man called Napoleon?