After receiving an antidote from Haibara, Conan temporarily turns back into Kudo Shinichi so he can go on the school trip to Kyoto with Ran, Sonoko, and Sera. Shinichi meets his mother's friend actress Kurachi Keiko at Kiyomizu Temple. She asks Shinichi to decipher a code delivered to her former college classmate Nishiki. While trying to crack the code, Shinichi receives a message from Keiko telling him to come to Nishiki's room, where he finds Nishiki lying on the floor upside down and bleeding from the chest with two bumps on his forehead...

In an unexpected turn of events, Ayumi becomes friends with Saki. Conan and his friends learn of Tazuko, Tachibana, and Michiyo, all of whom view Saki in a baleful way. They then learn all three of their apartment buildings can be seen from Saki's window. Tazuko's apartment is in a blind spot, but Conan and his friends believe it's possible Saki has seen Tachibana and Michiyo's secrets from her window. However, after questioning the three of them, they learn none of them hate Saki. They believe their fears were groundless, but then...