While Inspector Jugo Yokomizo interrogates the three, the Detective Boys try to figure out the meaning of the dying message. Conan realizes that on Akamine's watch, the word "Fish" is scratched out and finds out the meaning of the dying message. Conan reveals Aosato Shuuhei is the name spelt when the Kanji of Fish is removed from the dying message. He reveals Aosato cut Akamine's diving regulator and leaves her on the island after promising he would return with help. After she died Aosato returns and exchanges the regulator to hide the cut and uses Akamine's regulator to leave, causing her lipstick to appear on his face. Aosato confesses his crime and reveals Akamine caused the death of their past companion Yoshirou and he murdered her in revenge. Aosato then unveils his knife and holds Ayumi hostage demanding an escape route. Subaru disarms him and saves Ayumi and Aosato is arrested. Later that night, Subaru is seen drinking bourbon whiskey.

Conan, Kogoro, and Ran pass through Mount Fuyana on their way home and are stopped by Misao Yamamura who instilled a road block in order to catch the Silver Witch, a woman who drives a White FD car and challenges people in a drag race. When the witch drifts, the tire makes a sound that sound like a woman screaming. Yamamura reveals his grandma raced against the witch but gave up when the witch drove into the air. Kogoro decides to investigate on the identity of the witch and returns to Mount Fuyana the next day, taking Conan and Ran with him. Upon meeting the witch, Kogoro has a drag race with her but stops when Conan reveals that the witch drove into a road less area. Kogoro tells Yamamura to stop all White FD drivers and wait for his arrival. Once there, Kogoro interrogates the three suspect pairs in order to find out which one of them is the witch.