"Where did you get this book?" He tried to sound only  mildly curious, though he wanted to rip the answer from her mind. She was smart enough not to look him in the eyes. He was a skilled Legilimens, and if she had met his gaze he would have been able to take the answer from her without much fanfare. Since she refused to meet his gaze, getting the information would require a vocalized spell and it would be louder, messier, and take more time than he currently had.