I posted this in another topic since it would be useful to find who the boss was. But they I saw this topic. So I'm posting again, part of the other post and adding more. As far as his relationship with vermouth is considered, now I'm just shooting in the dark
Judging by vermouth's loyalty for the BO boss ran and shinichi (though she may twist their words to do her bidding, like going after haibara indirectly - seems like there is real good reason) it could be that she the boss's mother, sister, daughter, wife - as being his friend or lover is not that shocking or a reason to be kept a secret. Her reluctance to let haibara live and hatred for the drug seems the same as her secret relation with the boss. Also divulging a bit, usually a woman - especially an actress, would never resent the fact that she has stopped aging unless it had huge repurcussions - like losing her beloved, family or child or all of them. She now seems like someone who wants the nightmare to end and trusting shinichi as the silver bullet that will destroy BO. I dont know if she wishes the boss's death or just his defeat. Maybe she trusts shinichi is because he wont let anyone die. unlike shuichi akai who would snipe the boss if he knew who he was ? So would that mean she wants the boss to be spared but stopped? And she probably thinks shinichi is the only one who could do that like he did to her. Also, the boss has some sort of connection or understanding that vermouth won't betray him even if she strays. That speaks something about their relationship. And the reason for vermouth being so loyal is same as she is for shinichi or ran. so it's possible she considers/considered the boss as her ray of hope(like her own child)/saviour(sister,parent - adoptive or half or step)/benefactor(sister,parent - real, adoptive, half or step).And bourbon probably deduced it, meaning - shinichi can too and thus find who's the boss. Now if I existed in the dc world, I could look more into vermouth and people around her before her debut or accidents of some kind and figure out who the boss is. Of course, that would be the last thing I do because gin would kill me or maybe vermouth herself like she did with jodie's family . But, atleast I would know the boss's identity before I die.
