Nowadays Alberi was quiet. In class, that is. He was angry at himself. When he came here this year, all he thought about was his little sister. That completely made him forget stuff, in the end he even got a mistake in Potions. Later that day did he think over the whole situation and noticed how foolish he was for disliking his sister. He acted so... Immature. And he was the guy who read psychology books in his free time. The dislike towards her was stupid, he realized it was jealousy that she was getting attention. Only two things make you have sone hatred of something - the person is like you or they have something you don't. And he fell in that trap.
So, now he was punishing himself. He wouldn't speak in class, only doing whatever he should do. It wasn't like him and some teacher might notice but he didn't care. He wasn't really good with his sister, therefore he should face the consequences. He also promised himself to take care of her during the vacations. Which was amazingly out of character, mind you. Perhaps he should get more answers wrong. Though, honestly, besides his affection towards his sister, he hadn't changed, he was still the same gloomy guy who ignored the whole castle.
Now he had Defence Against the Dark Arts. He quickly read the board and only thought of what the spell did before waiting. He waited for the class to start, waited for the questions to be asked and answered, waited to be told what to do. As soon as he learnt it, he took out his wand quickly and thought over where such objects could be hidden. He went over to different places of the room and concentrated on the spell. He decided to ignore that he should tell the professor when he found one - someone else could find it, perhaps... No, he really was just continuing his punishment, though it was pretty foolish this time.