Some of the latest film's inventions do not bother me much. Allowing the Weasley brothers to set a firework dragon after Dolores Umbridge during the O.W.L. exams was almost as fun as turning one wing of the school into a swamp, and letting Cho reveal to Umbridge the Room of Requirement while under the sway of veritaserum instead of having a peripheral member of Dumbledore's Army turn traitor helped streamline the narrative (and cut out a peripheral character). I would, however, have liked more of the dots connected for non-readers of the book (is it wrong to assume such viewers exist?). Fred and George Weasley's various jokes and illness-causing edibles are more amusing if one knows Harry has secretly funded their experiments, and knowing that Luna Lovegood's father runs the Inquisitor-like rag "The Quibbler" would sure help explain her ridiculous claims about nargles and other unheard-of creatures.

Still more problematic were alterations of key narrative elements from the novel. This particular viewer couldn't help but cringe at the way director David Yates's Harry Potter: The Order of the Phoenix (2007) bypasses the significantly ominous new song sung by the Sorting Hat at the beginning of this school year, a song which emphasizes the new importance of crossing borders and creating new ties among the four, competitive houses at Hogwarts. Yates also considerably shortens the book-long period of angst experienced by Harry during which he wonders why Dumbledore continues to avoid looking at him, prompts the extremely private Neville to explain the painful origins of his parents' mental illness instead of letting Harry learn the tale obliquely, introduces the house elf Kreecher but neglects to mention his complicity in the near-fatal trap set for Harry, and skips over the kids' climactic journey through the various odd rooms in the Department of Mysteries (each of which provides unique challenges for different members of the adventuresome group).

My wife's audible reactions to a few elements of the story, however, verified for me early on that Yates was nailing some of the story's more important beats. Characterization is key, and Yates's direction of the films' wonderful, ever-expanding acting troupe produced near-perfect results. Helena Bonham Carter's frenzied version of Bellatrix Lestrange perfectly captured the character's wild mix of cruelty and craziness, and neophyte Evanna Lynch successfully rendered the hard honesty, subtle kindness, and peculiar otherworldliness of Luna Lovegood. The rude little titter emitted by Dolores Umbridge (Imelda Staunton) each time she interrupted someone to voice yet another Ministry-backed criticism of Hogwarts prompted consistent, painful sighs from Tracey, and I heard a few sniffles during some of the film's more heart-rending moments. The latter included Umbridge's attempted ousting of Emma Thompson's Professor Trelawney (a masterfully rendered scene, complete with compassionate Professor McGonagall and quietly furious Dumbledore), and those painful scenes bookending the movie which underscore Harry's profound--only briefly interrupted--sense of isolation.

In fact, those scenes that foreground Harry were undoubtedly its greatest strengths. Daniel Radcliffe has impressed me ever since I saw his David Copperfield in Simon Curtis's adaptation of the Dicken's novel (1999), but this film finally provided him enough space to demonstrate his amazing range (a range expanded, I'm sure, by his recent work onstage in Equus). Take the battle in the Department of Ministries. Notice the horrifying shift from confident enthusiasm to heart-tearing agony that occurs when the man alongside whom Harry is successfully fighting, his foster-father Sirius, is suddenly eliminated by Bellatrix. Watch the way the entire length of Harry's body bends sinuously when Voldemort later possesses him, as if the snake-controlling, Parseltongue-speaking villain has turned Harry into another of his scaly slaves.

The question of whether the venous-tongued head of the Slitherin house, Snape, is himself under the sway of the Dark Lord has long competed with Harry's own character journey for my interest. Even before the sixth book thrust Snape's ambiguous character into the spotlight, I had become convinced that Snape's identity crisis would become crucial to the series' resolution.

I will not know until this weekend (the final book comes out tomorrow night) whether my hypothesis is correct, but I've long felt Snape was to this series what Darth Vader was to the original Star Wars trilogy--or the magician Raistlin was to the DragonLance chronicles--an unpleasant and belligerent turncoat whose surprise redemption would prove as salient as the more predictable triumph of his heroic adversary.

In Rowling's The Order of the Phoenix, we finally found a chink in Snape's misanthropic armor. We ventured back into the past along with Harry and witnessed a young Snape's abuse at the hands of Harry's father, then a fellow student at Hogwarts. This scene was important not only because it revealed Snape's humanity and vulnerability, but because it shattered the monochromatic lens through which Harry had hitherto viewed the world. Harry had long assumed his father and friends must have radiated virtue in all their dealings with others, and that the adult Snape who mistreated Harry in potions class would have been similarly powerful and abusive as a kid. This sudden confrontation with the truth puts Harry's worldview into a tailspin from which he only emerges when it appears that Snape has unequivocally reestablished his villainy at the end of book six.

Unfortunately, Yates's film captures Harry's chance encounter with the truth, but does not explore how this new knowledge complicates Harry's reassessment of the boundary dividing good and evil. It is a psychological conundrum which Rowling intends the reader to step into, and Yates has done us a disservice by not inviting his own audience to so thoroughly question Snape's true nature. I have to believe that this is so because Yates, who must have been told by Rowling how the entire series will end, is saving his deceptively equivocal treatment of Snape for film six (which he is directing for a fall 2008 release).

I look forward to seeing more of Snape in Yates's next offering, which I predict will showcase the greyness of Snape's soul to prepare us for his redemption in the final film. I make these predictions as a leap of faith--Rowling just has to redeem Snape in the book that comes out tomorrow. She just has to . . .