How we cite our quotes: All quotations are from Harry Potter and the Half-Blood Prince.
Quote #1
MALFOY: Didn't Mummy ever tell you it was rude to eavesdrop, Potter? Petrificus Totalus! Oh yeah, she was dead before you could wipe the drool off your chin.
Whoa, that is a low blow, Draco. Harry is super haunted by the loss of his parents at such a young age, and Draco is just poking at that raw nerve. Not cool.
Quote #2
SLUGHORN: Merlin's beard! It is perfect! So perfect, I daresay one drop would kill us all!
Slughorn makes the kids concoct a "living death" potion in class, and Harry makes a good one. Sure. What could go wrong? Slughorn's statement is, er, a compliment. These Slytherin types are all kinda strange, no?
Quote #3
HARRY: So, what happens to you? What happens if you break an Unbreakable Vow?
RON: You die.
Dun dun dun. Err, yeah, so Snape made an Unbreakable Vow to help Malfoy along with some mysterious mission, which means that if he fails or refuses to do so, he'll die. That's a pretty hardcore promise, and it helps convince…well, basically everyone that Snape is no longer working for the good guys.