Well, im new here but i've been an dc fan for years.. If i remember correctly, Gosho said that Ai Haibara will be surprised if she found out, who is the BOSS.. For me, i think the boss is her father Miyano Atsushi.. Coz if, its Agasa-Hakase or someone close to Conan&Ai, why did Gosho only said that Ai will be surprised? If its someone Conan met, since Ai&Conan are often seen together.., then wouldnt Conan also be surprised? Since Conan doesnt know much about Ai's father then its a possibility that Miyano Atsushi is the BOSS.. Coz unlike Ai's Sister&Mother, We havent heard much about Miyano Atsushi except that he was called "The Mad Scientist".. Well hope i make sense here