Harry Potter and the Sorcerer's Stone
"I've heard of his family," said Ron darkly. "They were some of the first to come back to our side after You-Know-Who disappeared. Said they'd been bewitched. My dad doesn't believe it. He says Malfoy's father didn't need an excuse to go over to the Dark Side." (6.262)
"No – he wouldn't," she said. "I know he's not very nice, but he wouldn't try and steal something Dumbledore was keeping safe."
"Honestly, Hermione, you think all teachers are saints or something," snapped Ron. "I'm with Harry. I wouldn't put anything past Snape. But what's he after? What's that dog guarding?" (11.29-30)
"Can't have," Hagrid said, his voice shaking. "Can't nothing interfere with a broomstick except powerful Dark magic – no kid could do that to a Nimbus Two Thousand." (11.105)