and after what that girl had been through , neither of the detectives would have blamed catherine for thinking not ; but cori couldnt leave it there , despite her own earlier calls for caution , you know sir , if the families are linked then its obvious what her secret was yet grey merely placed his head back square against the headrest and faced forward , as if restraining himself from answering , as if saying to himself and so to them both that without the proof then this was a road along which he would go no further .