After making his way back to Gryffindor, Harry learned that Dumbledore had returned. He sprinted up the stairs to bring him the bottle containing the missing memory. They went into it and again saw the younger Slughorn sitting in a room surrounded by Hogwart's students. Tom Marvolo Riddle asked whether one of the other professors was retiring; they heard Slughorn complementing Riddle on being more knowledgeable than most of the staff; they saw that, although not the oldest, the other students looked up to Tom Riddle; they then, again, heard Riddle ask Slughorn about Horcruxes. This time, they heard the part that had been missing, or Slughorn's response. They heard Slughorn say that Horcruxes were "very Dark stuff, very Dark indeed" and that the only way to create one was by splitting the.....
