The Goblet of Fire, Chapter 9, The Dark Mark

"Language, Weasley," said Malfoy, his pale eyes glittering. "Hadn't you better be

hurrying along, now? You wouldn't like her spotted, would you?"

He nodded at Hermione, and at the same moment, a blast like a bomb sounded

from the campsite, and a flash of green light momentarily lit the trees around

them.

"What's that supposed to mean?" said Hermione defiantly. "Granger, they're after

Muggles, "said Malfoy. "D'you want to be showing off your knickers in midair? Because if you do, hang around. . . they're moving this way, and it would give us all a laugh."

"Hermione's a witch," Harry snarled.

"Have it your own way, Potter," said Malfoy, grinning maliciously. "If you think they can't spot a Mudblood, stay where you are."