Sirius Black: The Death Eaters at the World Cup, your name rising from that goblet... these are not just coincidences. Hogwarts isn't safe anymore.

Harry Potter: What are you saying?

Sirius Black: I'm saying the devils are inside the walls. Igor Karkaroff? He was a Death Eater. And no one, no one stops being a Death Eater. Then there's Barty Crouch. Heart of stone. Sent his own son to Azkaban.

Harry Potter: You think one of them put my name in the goblet?

Sirius Black: I haven't a clue who put your name in that goblet... but whoever did is no friend to you. People die in this tournament.