Although the Ravenclaw still had his doubts, he decided to trust him for now and nodded his head. Even if he still looked somewhat worried. What he said next made him look away from the fire and he raised an eyebrow. Did the Arithmancy Professor just say that he thought that numbers could become dull? He couldn't help it, he let out a laugh which he quickly masked as a cough. Force of habit these days. "I quite enjoy working with numbers" he said with a shrug of his shoulders. But he only had to work with them few times a week...not all day.

At the mention of the book, Dorian leaned a bit to the side so he could look over to the desk to which the Professor was pointing at. And he couldn't hide his disappointment on his face once he saw how old and worn out it looked. "...well i guess i can't read it in the library..." he was sure that the librarian was not going to appreciate the worn out and obviously falling apart soon book. "But..eh...thanks?"

After a few moments of looking around in silence, Dorian began to tap his fingers on the seat in a unconscious rhythm. Had the Professor forgotten why he was here? Should he ask? Or was that rude?