So, what curse shall we see first? Weasley! Yes? Stand! Give us a curse. Well... my dad...

Professor Moody: So, what curse shall we see first? Weasley! Ron: [scared] Yes? Professor Moody: Stand! [Ron does] Professor Moody: Give us a curse. Ron: Well... my dad did tell me about one. The Imperius Curse? Professor Moody: Oh, yeah, your dad would know all about that one. Gave the Ministry a lot of trouble at one time. Perhaps this will show you why. [opens a jar full of spiders and picks one out] Professor Moody: Hello, my little beauty! Engorgio. [the spider grows to a huge size] Professor Moody: Imperio! [the spider begins hopping around the room, onto student's clothes, faces, etc. Everyone starts laughing] Professor Moody: Don't worry, she's completely harmless! If she bites... she's lethal! [laughs with everyone] Professor Moody: Talented, isn't she? What shall I have her do next? Jump out the window? [the spider jumps toward the window, which is closed, and slams into the glass. Everyone stops laughing at once] Professor Moody: Drown herself? [the spider jumps to a pail of water and poises on the rim, ready to dive. Then he brings her back to his arms] Professor Moody: Scores of wizards and witches claimed that they only did You-Know-Who's bidding under the effects of the Imperius Curse. But here's the rub... how do we sort out the liars?