“Spare bit of parchment,” he said ugg sale with a shrug.
Snape turned it over, his eyes on Harry.
“Surely you don't need such a very old piece of parchment?” he said. “Why don't I just — throw this away?”
His hand moved toward the fire.
“No!” Harry said quickly.
“So!” said Snape, his long nostrils quivering. “Is this another treasured gift from Mr. Weasley? Or is it — something else? A letter, perhaps, written in invisible ink? Or — instructions to get into Hogsmeade without passing the Dementors?”
Harry blinked. Snape's eyes gleamed.
“Let me see, let me see…” he muttered, taking out his wand and smoothing the map out on his desk. “Reveal your secret!” he said, touching the wand to the parchment.
Nothing happened. Harry clenched his hands to stop them from shaking.
“Show yourself!” Snape said, tapping the map sharply.
It stayed blank. Harry was taking deep, calming breaths.
“Professor Severus Snape, master of this school, commands you to yield the information you conceal!” Snape said, hitting the map with his wand.