Conan and Ran enjoy the view from a luxury cruise ship, whose owners are charitably giving them a ride back to Tokyo since Kogoro forgot the departure time of their original boat. Conan and Ran notice another passenger, Natsue Hatamoto, who just married her husband, Takeshi, on the island they just left. Natsue's grandfather, Gozo, the head of the Hatamoto family and businesses, rants at the eldest son, Kitarou, for allowing non-family members onto the ship. Natsue's uncle, Joji Hatamoto, muses that Gozo's bad mood is likely from Joji cooking Western rather than traditional food. Gozo also belittles Kitarou's son, Ichirou, for being an artist and pursuing a hopeless dream. Gozo then orders Takeshi to come visit his room before dinner, and leaves. After he leaves, the disdain his descendants feel for him is revealed as Kitarou's wife, Mariko, Natsue's older sister, Akie, and Akie's husband, Tatsuo, argue over who will inherit everything after Gozo finally dies. Akie whispers shocking information to Mariko and mentions that there is only the twenty-four hours of the cruise to try to change anything.
Meanwhile, Gozo confronts Takeshi over the fact that Takeshi's identity is fake, and demands to know how he intends to avenge his father, though how Gozo wronged Isao Zaiki is not mentioned. Takeshi does not answer, but someone in the shadows overhears the conversation. As the family assembles for dinner, the butler goes to summon Gozo and finds the flower that Natsue gave Takeshi earlier just outside the door. Takeshi arrives at dinner a bit late and says he was thinking alone in his room, just before the butler's yell summons everyone to discover Gozo's dead body.
