This episode is critical for its introduction and development of major "Vermouth Arc" characters:

Building on the tension of Part 1, the episode follows Conan as he attempts to outsmart two bus hijackers who have taken a transit bus hostage to demand the release of their leader, a jewelry robber. The Accomplice

If you are curating a list of Detective Conan episodes to introduce a friend to the serious side of the series (beyond the comedy), put Episode 231 at the top. It is dark, intelligent, and emotionally resonant—everything that makes Detective Conan a timeless anime.

It is the conclusion of a two-part story that began in Episode 230.

9.8/10 Best Moment: Conan whispering to Haibara in the final scene, reassuring her that he will never let the Organization take her. Worst Moment: The false alarm regarding the Black Organization—though frustrating on a first watch, it is a brilliant subversion of expectations.