"You will be brewing it in this room, we have bewitched the door to repel anyone except those of us inside it now. If you decide to  not  go through with the process the room will also repel you. Do not try to bring anyone else into this room - it will not be a kindness you are doing them." Slughorn shook his head as he spoke quietly, clearly imagining the consequences in his mind's eye, this only made Draco even more curious.