** spoiler alert ** 
 I should give this four stars for the good writing, I know...I just wasn't that interested in the plot. I don't care about stamp collecting; even though the book explains why these stamps were so valuable I wasn't into it, yet I was frustrated when the old guy burns that one. He didn't seem like a selfish twisted maniac, he seemed reasonable and even wise before that, so why would he just burn something that he cared so much about and which was so valuable? 
 Flavia is a smart charater, as the book uses her knowledge and passion for chemistry in a clever why, helping her to make discoveries about the criminal plot. But like most mysteries, there were too many coincedences that led Flavia to solving the crime, like bumping into the pianist/piano teacher those two times. It bothered me that he is so short his feet don't reach the ground as he sits, yet he was a famous concert pianist. I think his fingers would be too small.