Ian really, really wasn't liking this professor Cassie. She was mean and she didn't treat her students well and that wasn't the Professor Cassie he knew AND loved.
Professor. I did write something on one of those slips, but not because of pride or any of that stuff, but because it was something you wanted us to do. You were my favorite professor, but now I don't know. You have changed. You're acting like.... he thought a minute and then continued
Well...I don't know, but you don't make me feel all happy like you have before. You're being mean and if I have to go to the dungeon for saying so, I guess I'll be in the dungeon.
Then, she told them to go pick a mirror. He just sat in his seat. He wasn't going to do ANYTHING for this mean woman until the REAL Professor Cassie came back. This woman wasn't teaching, she was demanding and that didn't teach anyone. Even that horrid woman in Arithmancy had at least provided some instruction.
Professor, why don't you start TEACHING and do less DEMANDING. This is a class, not a meeting of your underlings! Ian was hurt at how Professor Cassie was speaking to him and he responded in kind.