Grade: C+

The last two “Harry Potter” movies were so good that perhaps it’s inevitable this fifth installment in the franchise would be a disappointment. But the comparative weakness of “Harry Potter and the Order of the Phoenix” isn’t due to the filmmakers or the cast, who all do solid enough work. It’s the fault of the script and—presumably—the book by J.K. Rowling on which it’s based. Simply put, this chapter of the story feels like it’s just biding time; the crux of the plot—that virtually nobody believes Harry’s insistence that The Dark Lord has returned except his closest friends, and the general skepticism has to be overcome by solid evidence—seems nothing more than an authorial contrivance designed to prolong the overall narrative. One can see the point that Rowling is making—that in order to fulfill his destiny, Harry must learn to lead by going through a crucible of fire. But the way she and the adapters have chosen to dramatize this leads to a picture that’s surprisingly slow, soft and—to put it bluntly—unexciting. And in the final analysis it doesn’t significantly advance the plot. After nearly two and a half hours, we find ourselves at the end pretty much where we were in the beginning: Voldemort is back, and it seems inevitable that there will be a climactic showdown between him and Potter.

That doesn’t mean that things don’t happen in the movie, of course. Much of the running-time is dominated by the figure or Dolores Umbridge (Imelda Staunton), a prim, pink-garbed horror of a teacher sent to Hogwarts as a check on Headmaster Dumbledore (Michael Gambon), whom his archrival the Minister (Robert Hardy) suspects of conspiring against the status quo by embracing Harry’s (Daniel Radcliffe) preposterous fantasy about Voldemort’s (Ralph Fiennes) resurrection. Umbrage not only defangs the Defense Against the Dark Arts course, turning it into a purely theoretical exercise of no practical value, but becomes the campus inquisitor—a post she uses to persecute Potter—and eventually headmistress. To counter her, a small group of Harry’s classmates, led by Hermione (Emma Watson) and Ron (Rupert Grint), persuade him to teach them spells, forming an underground junior-league contingent of the Order of the Phoenix, a secret organization to which he’s recently been introduced by his godfather Sirius Black (Gary Oldman). Much screen time is devoted to their training exercises, hidden from the suspicious eye of Umbrage and her little Gestapo band of anti-Potter student supporters, led of course by his inveterate enemy Draco Malfoy (Tom Felton).

These two major plot threads ultimately come together in a big confrontation, of course—this time in a huge warehouse-like floor of the Ministry of Magic, where Harry and some of the intrepid members of Dumbledore’s Army, as they call themselves, must face off against a group of Voldemort’s minions and, ultimately, the Dark Lord himself. As one of those who haven’t read the book on which the movie is based, I can’t be entirely certain of this, but it seems that the entire scenario has been stage-managed by Voldemort, via visions he implants in Harry’s terrifying dreams, to draw the youngster to him in order to retrieve some sort of prophecy that lives within one of the thousands of crystal balls housed in the Ministry.

And that confusion is one of the biggest problems with “The Order of the Phoenix.” While the particulars of the plot might be perfectly clear to those who have assiduously followed Potter’s story in Rowling’s books, scripter Michael Goldenberg (replacing Steve Kloves) and director David Yates (succeeding Mike Newell) don’t sufficiently clarify matters for non-fans: the general outline is straightforward enough, but the details are obscure and the connections aren’t sufficiently well drawn. That wasn’t a defect of previous installments (as least not for this viewer), and the fact that it is one here suggests that the fault lies with the new adapters.

And there are further difficulties. This picture lacks the sense of wonder, in terms of CGI effects, that the previous two films in particular so effectively conveyed. There are a few such moments, like an opening encounter with some Dementors and a later ride atop some flying dragon-like creatures, that strike fire, but others—forest sequences with some centaurs and with Hagrid’s giant brother most particularly—are not only surprisingly limp, but aren’t especially well executed from a technical standpoint. (At times they look like outtakes from an old Ray Harryhausen film.) Then there’s the excessive use of the old lightning-strike sorcerer’s combat, notably in the big finale. Seeing bolts of energy flash from wizards’ wands, gunfight-style, made the conclusion of “The Goblet of Fire” sag, and here the effect is even more unfortunate. It’s reminiscent of what we used to see in those dreadful old Sword and Sorcery movies, and goes on much too long besides.

And though the inherent grimness of this chapter of Harry’s story—he loses yet another person he’s come to depend on—is certainly defensible (the last two installments were far darker than the initial couple, after all), the young man’s despondency and fearfulness are conveyed in ways that just aren’t terribly interesting. Radcliffe has developed nicely as an actor as the series has progressed, but here he’s forced to suffer all too melodramatically: he writhes through nightmares and suffers the slings and arrows not just of Umbrage but of his unbelieving classmates endlessly, coming across like some adolescent male variant of Camille. And while Watson and Grint continue to offer strong positive support, others in the regular company—past and present Hogwarts teachers Robbie Coltrane, Alan Rickman, Emma Thompson, Maggie Smith, David Thewlis, Brendan Gleeson, and even Gambon, as well as such outsiders as Oldman, Fiennes, Richard Griffiths and Julie Walters—are given surprisingly short shrift here. (On the other hand, Helena Bonham Carter, as the shrieking villainess Bellatrix Lestrange, is given too much: a little of her scenery-chewing goes a very long way.)

There are some additions of note, however. One, of course, is the estimable Staunton, who brings a flawlessly stern-with-a-smile demeanor, as well as a perfectly gauged little giggle, to the role of the petite but dictatorial Umbrage. (Production designer Stuart Craig, supervising art director Neil Lamont and set decorator Stephenie McMillan, whose work is superb throughout—unlike that of Nicholas Hooper, whose background score is bland and forgettable—have also outdone themselves with the interior of her office, a marvel that matches the distinctive wardrobe designed for her by Jany Temime.) It isn’t her fault that the part is a one-note routine that palls over the long haul. The other new figure of note is new girl Luna Lovegood, played by Evanna Lynch, who brings an appropriately ethereal air to the role even if her thin, pinched voice forces one to strain to understand some of her lines.

There’s no doubt that “Harry Potter and the Order of the Phoenix” will be a must-see for fans of the books and the previous films, and as a link in the series it will do. (After all, it could hardly have been designed as a stand-alone experience for the completely uninitiated.) But after the exceptional quality of the last two installments (especially “The Prison of Azkaban,” still the best of the lot), it’s a letdown. Let’s just hope that the dip is an isolated one, and that the grading over the entire run of seven films doesn’t come to resemble a bell curve variant in which the ratings start low for the first two films, rise to a height for the next two, and then suffer decline over the last three.