[It was kindness in a way, not wanting to kill anyone unnecessarily. If he wanted to kill her he could do it now with very little to pay for it, but he doesn't want to. He doesn't take any particular joy out of killing students, though many who enter his classes will meet that fate.

Now, hunting down and killing people who deserved it was another matter. That he enjoyed. That he was particularly good at.

Once she is in the library he follows suit, setting down his own books to the librarian. They exchange a couple words, seemingly familiar with one another before he holds the door open for her once more.

He wasn't mannerless afterall.]

I understand you may not wish to be in my presence any longer. I will leave you to clear out that room and go searching for other books.