Central to the mythological ‘Hero’s Journey’ is a descent to the ‘underworld’ - a symbolic death from which the hero emerges transformed. Many have noted that the Harry Potter books have so far included these journeys; in each book, Harry descends into an underworld of some sort.
These are not symbolic journeys to the underworld merely because they are underground, however; each is the catalyst for significant transformation in Harry-as-Hero.
The themes of the Harry Potter books are many, but underlying the series is the most basic and central theme of all: Good and Evil. Voldemort is the clear representation of Evil, and Harry, despite his faults, is the Hero, and is symbolic of Light and Good. In each of Harry journeys to the underworld, and in his subsequent emergences, I believe he undergoes a transformation in his own concepts and knowledge of Good and Evil.
In Harry Potter and the Sorcerer’s Stone, Harry’s journey to the underworld is clearly apparent as such. He journeys down underground, entering through a trapdoor which is guarded by a three-headed dog, clearly the equivalent of the three-headed Cerberus which guarded the entrance to the underworld in Greek Mythology. The transformation that Harry undergoes in this underworld is of major significance. Previously, Harry had known of evil, and his life had certainly been drastically affected by evil, but it is only when confronted with Voldemort for the very first time that he truly encounters Evil and grasps just what it is that he is fighting against. On this journey, in this underworld, Harry recognizes and acknowledges Evil, and by undertaking this journey, Harry accepts the role of Hero and Savior.
In Harry Potter and the Chamber of Secrets, the journey to the underworld is Harry’s journey down into the Chamber of Secrets. It is in the Chamber that Harry’s understanding of evil matures. He is faced with Evil not at its pinnacle but at its beginnings, and he is forced to acknowledge - whether consciously or subconsciously - that it is humanity that begets Evil, that Voldemort was once human. His recognition of the similarities between himself and Tom Riddle strengthen this message, and this recognition, along with Dumbledore’s explanation to Harry that there is some of Voldemort in him - the reality that Harry is tainted by evil, has some evil within him - makes it clear that there is the potential for Evil in every human. Yet in the Chamber, Harry is heralded as Hero and Good by Fawkes, and it was only by means of using his Voldemort-derived talent of Parseltongue that he was able to assume the role of Savior, and Dumbledore assures Harry that it is his choices that determine whether or not he is Good.
In Harry Potter and the Prisoner of Azkaban, Harry does not meet Voldemort face-to-face. However, he does journey down into the underworld, and he most certainly undergoes another transformation in his understanding of Good and Evil. When Harry descends beneath the Whomping Willow and discovers the truth of Peter and Sirius, Good becomes Evil and Evil becomes Good. What Harry learns - a vital lesson indeed - is that Good and Evil are not always readily apparent.
In Harry Potter and the Goblet of Fire, the underworld is not actually a place below ground; instead it is a cemetery. A cemetery, as the ultimate symbol of death, can be viewed as an above-ground underworld. In the cemetery, Harry truly experiences evil for the first time - through the death of Cedric, and by facing the full power of Voldemort - and Harry is, for the first time, unsuccessful at defeating the evil. He escapes, but certainly he does not defeat Voldemort - and thus must face the grim reality that evil does irreparable damage and cannot always be overcome.
In Harry Potter and the Order of the Phoenix, the journey to the underworld is the journey underground into the Department of Mysteries. There is additional death and underworld symbolism here, in the form of the Thestrals. Both skeletons and wings are traditional gravestone symbols meaning death, and the Thestrals are little more than flying skeletons. To add to the death symbolism, in many cultures/mythologies, Death is seen as being carried or pulled by black horses. And of course, Thestrals can only be seen by those who have seen death. Thestrals are death personified, and it is they who transport Harry and company to the underground in this book. In the Department of Mysteries, Harry is transformed by his loss of Sirius, which makes him even more determined to stand against Evil, but on a deeper level, Harry is transformed by the fact that he has been possessed by Evil and yet has managed to overcome it with his essential Goodness. The lesson here - whether or not Harry has yet consciously acknowledged it - is that fundamentally, Good is stronger than Evil.
In each of the books, then, Harry’s understanding of and attitude towards evil deepens and changes through a journey to a symbolic underworld.
It seems, too, that there are parallels to be drawn between the lessons of books 1&4 and books 2&5, and I would speculate between books 3&6 as well…. After all, Goblet of Fire marks the turning point in the series, when evil is reborn and becomes a much larger and stronger presence in Harry’s life; it makes structural sense for books 4, 5, and 6 to teach Harry the same lessons as books 1, 2, and 3, but on a deeper and more powerful level…. And then, of course, book 7 would be some sort of culmination.
In SS/PS, Harry faces Evil for the first time - but the Evil is in a weakened form. In GoF, Evil is reborn, stronger than ever, and Harry experiences true Evil for the first time.
In CoS, Harry discovers that there are strange similarities between himself and Voldemort, that Voldemort put some of his powers inside himself; yet Dumbledore tells him that his choices determine his innate Goodness. In OotP, Harry is possessed by evil, but his innate Goodness overcomes the evil.
In PoA, Harry discovers that what seems Good can really be Evil, and what seems Evil can really be Good - and that Good can become evil. Will Harry experience a more personal betrayal in HBP? Will someone Harry thought of as evil somehow redeem himself? I am certainly looking forward to finding out... and I look forward to seeing the underworlds into which Harry will be descending in books 6 and 7.
Comments, thoughts, and further speculation very welcome and much appreciated.