her forebrain supplied logic ; this other part supplied an almost incoherent imperative : dig on it , bobbi , it 's okay , dig on it , dig on it , shit , why not dig on it a while more , you know you want to know what it is , so dig on it till you see what it is , dig dig dig she was able to turn the voice off by conscious effort and would then realize fifteen minutes later she had been listening to it again , as if to a delphic oracle .