[ If his hands weren't full of books, he would have waved a hand in apology for startling her. ]

Oh, no. I'm sorry for approaching you all of a sudden. [ In retrospect, he should have been a bit more delicate. ] I just wanted to know, because I thought it would be easier if we helped each other with the research?

[ He makes sure to leave that a question, just so she won't think he's imposing on her. ]