2017 book 136

J.K. Rowling's Harry Potter and the Half-Blood Prince
You know I have read these books too many times and spent way too much time thinking about them, but I still can't puzzle out how the detection of underage magic works. So in past books, the Ministry could tell when anyone (Harry or Dobby) did magic in Privet Drive, and in this one they say that the ministry doesn't track this (as far as I can tell) in wizard homes, because they rely on parents to monitor children's behavior. And then there is the whole thing with the Trace in book 7, which implies that the Ministry CAN detect specific underage wizarding magic. My point is: how can Dumbledore do a whole bunch of magic in Privet Drive in this book and no one says a thing? (Similarly, we don't SEE Arthur Weasley use magic there in the beginning of book 4 but it is implied that he used magic to repair the living room.) Is it like a proximity thing, and it's just that Dobby was closer to Harry than Dumbledore was? Am I (definitely) spending more time trying to figure this out than JK Rowling did? Anyway, I like this book, Harry is kind of a doof but backstory and teen hijinks are entertaining and the end packs a wallop.