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 et Subaru parviennent tous deux à déchiffrer le code laissé par la jeune fille et à coincer le coupable. Ce dernier, cependant, prend Ayumi en otage et tente de s'enfuir. Subaru intervient et distrait le meurtrier avant de le désarmer. Okiya est ensuite vu en train de boire du bourbon dans la maison, tandis qu'Ai l'aperçoit par la fenêtre et pense "Il est...".
Sia Conan che Subaru riescono a svelare il codice lasciato dalla ragazza e ad inchiodare il colpevole. Questi, però, prende in ostaggio Ayumi e cerca di scappare. Subaru interviene e distrae l'assassino per poi disarmarlo. In seguito si vede Okiya bere bourbon in casa mentre Ai lo spia dalla finestra e pensa "Lui è...".
Haibara sigue notando la presencia extraña de Okiya. Tres hombres son sospechosos de haber matado a la chica, culpable que encontrará Conan y que los pondrá en una situación muy difícil de la que serán salvados por alguien inesperado.
Haibara segueix notant la presència estranya d'Okiya. Tres homes són sospitosos d'haver matat la noia, culpable que trobarà Conan i que els posarà en una situació molt difícil de la qual seran salvats per algú inesperat.
