This is my FAVORITE of the entire Harry Potter series! The development of Voldemort's early life through memories is the strongest part of the plot for me, but in general, I loved the way the author was able to unfold shocks and surprises despite the familiarity of the characters by this point in their Hogwarts education. The antagonist was really interesting (especially the very morally grey way he operates), and the book felt more mature than its "middle-grade" tag, which I appreciated since it felt like these books grew with their main characters.