You sometimes have to join forces with those you'd rather avoid.

“He will only be gone from the school when none here are loyal to him,' said Har…”

“I smell guilt. There is a stench of guilt upon the air.I see you all, whole and…”

“Now, I don’t want any of you youngsters to worry — you’ll still have your Potio…”

“Don't let the muggles get you down.”