"Over a decade ago, the Imperius Curse caused the Ministry of Magic more trouble than you can imagine." As Moody spoke, he struggled to his feet with the help of his prosthetic leg. He made his way behind the lectern, opened a drawer, and took out a glass bottle containing three enormous black spiders. They crawled restlessly inside.
Moody reached into the bottle, plucked out a spider, and placed it on his palm for everyone to see. Then he raised his wand, aimed it at the spider, and intoned, "Imperio!"
As though seized by an invisible force, the spider sprang from Moody's hand. It hung from a single strand of silk, swinging back and forth like a child on a swing.
Its legs stretched out stiffly. Then it turned and executed a perfect somersault. Unfortunately, the strand snapped, and the spider landed heavily on the desk. It promptly began turning somersaults across the surface.
With a flick of Moody's wand, the spider miraculously stood on its two hind legs and began a strange tap dance. Every step was bizarre, yet somehow perfectly timed.
The Slytherin students leaned forward. Some could not help laughing at the spider's ridiculous movements.
"You think this is funny, do you? Would you still find it amusing if you were the ones under this curse?" Moody's icy voice cut through the room.
The laughter stopped at once. Silence returned to the classroom.
"It's entirely under my command," Moody said. The spider curled into a ball and rolled around in his palm. "I could order it to leap out the window, drown itself, or even jump down the throat of any one of you..."
"Years ago, after You-Know-Who fell, countless wizards who had joined the Death Eaters claimed they'd been under the Imperius Curse." Moody glanced at