i think slughorn is hiding something from all of us about a different character maybe im crazy but everytime he messed up rons name such as rupert idk i just think that might give us our unknown R.A.B just a thought what do you think?
That would make for quite a book if Harry turned out to be the Horcrux because in order to defeat Voldy he would have to kill himself or be killed by someone but if he is killed than there is no one to kill voldemort which means that evil would prevail and i doubt J.K would do that to everyone. That'd be awful if they killed off Harry
Hmmm... could be that Slughorn's thinking of someone but I'll bet you ten Galleons that R.A.B is Regulus Black, Sirius's little Death-Eater brother.