He glares at the class as they dumbfoundedly stare back, "Any questions?" 
                          
The room remains silent; Willow assumed out of fear, or possibly from confusion. Taking the silence for a definite no, Mad-Eye carries on. 
                          
The Professor spins to write in scrappy penmanship on the chalkboard. The students sit still and shocked at the scratched words when Moody turns again to snap, "The three Unforgivable Curses. What are they?"
                          
The stiff silence is broken by Ron's tentative words, "Well, there's one I heard from my dad. The Imperius curse."
                          
Moody lets out a sound of realization. "He would know about that wouldn't he? Working for the Ministry, of course." With a sinister jab of his wand, he muttered the spell. Much to the students delight, the bug tapped his limbs in a merry dance against the wood of the desk. The roar of amusement grew when the insect jumped onto Neville in the front row, its body still prancing. 
                          
Moving from the Gryffindor boy the little beast landed on Draco, who immediately panicked. Laughter burst wildly from the young witches and wizards while Mad-Eye giggled manically. 
                          
The bug was then forced over to the windowsill as Professor Moody laughed, "Talented isn't she? What should I have her do next? Jump out the window?" The classes mood sombered as his did, he brought his voice to a deep state as he continued, "Drown herself?" The creature squirmed over a cauldron, desperately trapped inside of its own body.
                          
The class waited in a stirring silence for him to continue. With patience he finally spoke after bringing the insect back into his palm, "Scores of witches and wizards have claimed that they only did, you-know-whos bidding, under the influence of the Imperious curse. But, how do we sort out the liars?"
                          
Willow suddenly felt cold, like all the warmth of her blood had been drained. Under the iron grasp of the spell, there is no control over one's own body. They could be made to do anything - sell secrets to the enemy, kill themselves, torture their own family, betray close friends. 
                          
The rough Professor quickly moved on in asking for another one of the unforgivable curses. 
                          
Picking on Neville who sat in the front row, he eventually gave the name the second curse, "There's the... um, the Cruciatus curse." 
                          
"Correct! Correct!" He awarded the weary boy, "Come." 
                          
Neville hesitantly stood and followed the Professor to the front of the class where the bug sat peacefully on the table. "Particularly nasty," Moody explained, "The torture curse."
                          
As he spoke the words with his wand aimed, the insect began to squirm and scream in evident pain. Shrieks filled the room, and the staring students cringed. Neville flinched harshly, his features screwed up tightly on his paling face; it looked as if he was under the curse himself. Hermione finally spoke up in a desperate cry, "Stop it! Can't you see it's bothering him!? Stop it!"
                          
Moody looked to Neville shocked, before discontinuing the spell of torture. He coughed, clearly unsure of how to apologize, although he let the boy sit down as he gently picked up the bug once again. The professor walk awkwardly down the aisle with his unsteady gait, bringing the critter to the desk Hermione and Tessa shared. 
                          
"Perhaps you could give us the last unforgivable curse, Miss Granger." The witch simply shook her head, eyes fixated on her desk. Her reaction did not keep him from shouting, "Avada Kedavra!" 
                          
There is a flash of poison green light, leaving the creature deathly still. The class sat in that same stillness, so quiet that heartbeats could be heard.
                          
"The killing curse." The mad teacher rasped. "Only one person is known to have survived it, and he's sitting in this room." Professor Moody then advanced on the Potter boy that sat across the row from Tessa, she swallowed hard as her body shivered violently. She assumed Harry did the same.