Derek rolled his eyes, clenching his jaw and reminding himself that not only did he need this job but that prison would not be kind to him so murdering a student was probably not the best idea, not to mention that Stiles was obviously going through...something. He went to sit at his desk and grade the essays he'd given the fourth years.
After about twenty minutes, he glanced up at Stiles and then returned his eyes to his papers. "You have seemed off lately, Mr. Stilinski. Not nearly as talkative in class. And I have heard from some of your dormmates that you haven't been as active as you could be. Is there something going on?"