I don't usually ship people in mysteries, but Rowling has made up for the total mismatch of Ron and Hermione plus written a terrific mystery! No sneaky "oh I forgot to give you this clue 200 pages ago," no last minute suspects, just loads of information that builds until you have to start gleaning out what's important. The central blackmail/suicide mystery revolves around a subject I'd never heard of but one that should be better known. Well researched and beautifully written. I really like how conversations are real: people stopping to eat, being interrupted, just the stuff of real life.
But I have to admit, this book is heavy on the personal lives of the protagonists, and while I wrote the previous paragraph right after finishing the book, I'm already fuzzy on the mystery, but I sure remember where our heroes left off! And I have to admit to a good deal of trepidation about reading the next installment where it appears she may be doubling down on her anti-trans stance. I really hope that the negative hype is overblown.