Ludo looked around as a loud voice sounded from the room. To his surprise it was an unwelcomed visitor. Peeves.

The poltergueist flew madly across the class and began acting like their Potions master. To Ludo's horror, Peeves took cupfull after cupfull of the potion and began hurling it around the class.

Ludo pulled out his wand, unsure what good it would do, but soon found a good reason. A cup of potion was flying right at him and he barely had enough time to raise his wand and breathe, "Protego!"
The potion splattered on the shield and burst into a bright light.

He ducked for cover around a desk and shouted, "Peeves! You ruin the Restricted Section and have the nerve you disrupt our class!"