The City Hunter Case was a complicated affair, but due to the efforts of Gray Panther, it was successfully resolved.

The City Hunter Case was a complicated affair, but due to the efforts of Gray Panther, it was successfully resolved. With all the excitement of the past days behind them, Conan, Ran and Kogoro board the Bullet Train to Kogoro's friend's wedding. But their peace and quiet comes to an abrupt end when two men in black decide to join their train car. The two men begin discussing a carefully planned crime over a radio and they mention a bomb.

Source: https://ww4.detectiveconanepisodes.com/detective-conan-episode-5-english-subbed-watch-online/

In the movie, Ran and Shinichi Kudo (Conan's true name) play a game where they solve a murder mystery while they are on a train. Shinichi proclaims that he is not feeling well and retires to his cabin. He uses this time to go into the bathroom and change into Conan. After he solves the case, he goes back to his cabin where Ran comes in and says she knew it was him, but Shinichi denies it. After escaping from the grasp of Gin and Vodka, Shinichi hides himself from their clutches by turning himself into Conan. He pretends to be his own cousin by changing his hair color and using round glasses that give him fake eyes. Later on in the series, he meets up with Ran Mouri who is the daughter of Kogoro Mouri. As an homage to Holmes, Conan lives with Ran and her father for a few years as he tracks down Gin and Vodka to prevent them from harming his loved ones. With his friend Dr. Agasa's help, he creates detective gadgets that help him solve difficult cases such as the stun gun wrist watch and voice-changing bow tie

In the long-running series, Conan and Ran accompany Kogoro on the bullet train to go to Kogoro's best friend's wedding when Conan overhears two men in black talking about a bomb set to go off on the train. If Conan doesn't find the briefcase with the bomb in time, everyone's life is in danger. Detective Conan is one of the longest running anime and manga series, starting in 1996. A majority of the episodes are fillers meaning that it does not progress the plot or be noted later on. Meaning, there is no ending. Kogoro is invited to his best friend’s wedding, where he will reunite with his other best friends after an interval of 20 years. Ran, Sonoko, and Conan join him on the bullet train to Hiroshima. On the train, Conan overhears two men in black talking about an assassination plot against a person on the train. He also realizes that there are five assassins in total. Ben Evans and William Simms (two of the four previous FBI agents that ran away with Big Boss) are the two men in black who came up with the plan to assassinate Kudo Shinichi on board a bullet train by planting a bomb inside a briefcase and hiding it amongst the luggage