I have not been a part of the Harry Potter fandom, so I don’t know if anything I’m going to mention here has been answered in interviews or wikis, etc. I doubt Ms Rowling had the entire seven book series planned from the beginning. However, it’s pretty clear that sometime around book 2 or 3 she did a general outline of the rest of the series because it has all fight together so nicely – and not in a cheap way. Again, not having been a part of the fandom, I’m unaware if there’s some glaring plot hole, but overall it seems to fit quite, quite well. Each book matured not just in the tone of the prose and the subject matter, but also in the lifting of the veil of protection kids feel from adults. The adults were revealed to be selfish and have impure motives and, in the case of the worst of them, no problems being violent to children.
As for this book itself, I think it was rather well plotted. It did not have the unrealistic tone of so many heroic journeys in which all was always going right. Each of the three main characters has moments of selfishness, wrong or bad ideas, and things go quite horribly wrong for them at various points. While we know that generally, the heroes will triumph at the end, the route they take is full of best laid plans going wrong in ways that are very rarely expressed in any books whether they be young adult or regular adult books.
In addition to providing a respite before the final climax, the chapter in which we finally learn all of Snape’s backstory was a wonderful addition to the story. Dumbledore was glad to share various hints about why Snape was not as bad as Harry thought, but until reading this chapter, I didn’t realize how fully realized an antagonist he was. Combined with the revelation a few books ago that James Potter was no saint, Snape has quite the story arc.
Also tantalizing were the sections of backstory we finally learned about Dumbledore. Going along with my above-mentioned maturity of the series as time went on, we learn that Dumbledore was neither the Saint some believed him to be nor the secret Devil others suspected. He was a man and rather complicated at that. For a child that grows up reading Harry Potter it is an important lesson – our heroes are not perfect, but that does not have to make them any less heroic.
Finally, all books are a product of their times and I felt at times that the background of this series involved Ms Rowling either purposely or subconsciously probing the reader to think about tyranny and terror and what that does to people. The fear from both of Voldemort’s reigns kept people afraid enough to be controlled and to allow the innocent (wizards and muggles) to die. The Ministry and its constant lies (both under and not under Vodlemort’s influence) can’t help remind me of what happened during the early to mid-2000s both in England and USA as we were lied to about the situations abroad and our reasons for doing what we did. The racism against elves, muggles, and all the other categories was even shown to lead people to violence – witness Dumbledore’s backstory or those who were against Mudbloods while even their leader was one himself. It reminds me of the pious leaders of various groups who turn out to be into whatever it is they’re preaching against.