"But what can we —" Hermione gasped. Harry and Ron wheeled round.
Snape was standing there. "Good afternoon," he said smoothly.
They stared at him.
"You shouldn't be inside on a day like this," he said, with an odd, twisted smile.
"We were —" Harry began, without any idea what he was going to say.
"You want to be more careful," said Snape. "Hanging around like this, people will think you're up to something. And Gryffindor really can't afford to lose any more points, can it?"
Harry flushed. They turned to go outside, but Snape called them back.
"Be warned, Potter — any more nighttime wanderings and I will personally make sure you are expelled. Good day to you."
He strode off in the direction of the staffroom.