Fake Moody received no reply, but he did not seem to mind. He picked up the register again, his magical eye spinning as it swept over the young wizards' faces.
"All right, you, then." He called out a name at random.
The young witch whose name he called looked rather alarmed. She hesitantly rose to her feet; judging by her clothes, she was in Ravenclaw.
"Don't worry. Just tell us what you know," Fake Moody said.
"Er... I've only heard my uncle mention one..." The young witch swallowed. "It's called the Imperius Curse."
"Exactly. The Imperius Curse. This spell once caused the Ministry of Magic a great deal of trouble." Moody gestured for the young witch to sit down, bent over with difficulty to open a drawer in the lectern, and took out a jar containing three black spiders.
Without the slightest fear, he plucked a spider from the jar, placed it on his palm, and raised it for everyone to see.
Then Fake Moody aimed the wand in his other hand at the spider in his palm and spoke loudly enough for everyone to hear-"Imperio!"
A milky-white light flashed and vanished. It seemed as though something had happened, and yet as though nothing had happened at all.
The spider leaped from Moody's palm, shot a strand of silver silk onto one of his fingers, and swung back and forth in midair as though on a swing.
Then it straightened its legs and performed a backflip. The silk snapped, and the spider landed on the desk with a splat. It quickly scrambled up and began turning somersaults across the desk. Moody flicked his wand again, and the spider actually rose onto two legs like a human, planted its other legs on what might or might not have been its waist,