Nice setdown for Draco. It's weird seeing such a congenial relationship between Harry and Voldemort, but I'm getting used to it.
Harry was a little rude to Lupin - illness is generally a subject to be raised by the sufferer, not an observer. It's generally a sensitive issue. The conversation stands out because Harry had just mentioned the importance of good manners.
Great chapter, as always. Your version of smart Harry is terrific.
Author's response
The way that he raised the question of Lupin's illness actually made me hesitate for a moment, but it is in keeping with his character. Right now Lupin is not quite a person to him, he's a curiosity and something to be studied.