The viewer is lead to believe that it must to be one or the other of them, No.6 or No.2. That only one can leave the Embryo Room, is that "alive?" And if so, did No.2 foresee the possibility of his own death? I think he was afraid that it would be him that died. But if that's the case, why should it be either one of them, why not both? Because No.2 is a good man, was a good man until that episode The Chimes of Big Ben. There seems ot be no rhyme nor reason as to why No.2 should die. But was it No.2 who died in that cage in the Embryo Room? Recall the words of the Prisoner......."Die Six.....die.....die.....dieeeeeeee!" And don't forget that at some point in their deliberations, the patient had actually changed places with the doctor. So it was No.6 that the Prisoner wanted dead!