Brief excerpt of the introduction text of the essay I planned to write (in 2010) on the question How effective a conclusion does Harry Potter and the Deathly Hallows provide to Rowling’s sequence of novels? I never completed the essay, but I still like the premise.
Harry Potter and the Deadly Hallows, as the last book in Rowling’s sequence, concludes the series effectively by providing a satisfactory ending to the storylines, by returning to and complicating previous motifs and key themes whilst also tying up loose ends. Major themes that Rowling returns to in the final novel are the opposition between good and evil as well as tolerance and acceptance. Throughout the series, Rowling continually complicates and challenges the binary opposition between good and evil. Starting in HP and the Philosopher’s Stone, Quirrel is bad whilst Snape is good. In HP and the Prisoner of Azkaban, Sirius Black is good yet his actions are not always that of a good character: as a student he led Snape into mortal danger by having him enter the Shrieking Shack whilst Lupin is transformed into a werewolf. Likewise in HP and the Goblet of Fire, Crouch Jr as Alastor Moody is revealed as an evil character, yet towards Neville Longbottom he shows acts of kindness by talking to him after showing the unforgivable curses as well as providing him with a book of interest. In HP and the Deadly Hallows this complication of the difference between the moral appearance and reality is seen in the questionable history of Dumbledore as well as the final redemption of Snape. In relation to this theme, another motif in the series is tolerance. In the final book, tolerance and respect for minorities by the protagonists play a major role in the eventual triumph over evil. It is because of the respect Harry shows for house-elf Dobby, that the goblin Griphook decides to help them break into Gringotts. Furthermore, by showing kindness to Kreacher and listening to his tale, the protagonists are able to find and steal a Horcrux. In HP and the Deadly Hallows, Rowling continues to explore the themes of previous novels and demonstrates how only because of the characters choices and actions, good is allowed to triumph.