The Harry Potter franchise is pretty much a known quantity at this point. Based on the best-selling series of books, the films have set a standard of quality that they have largely stuck to, with the first two frigid installments setting a kind of bar for the lowest level of quality, and the Alfonso Cuarón-directed third entry, Harry Potter and the Prisoner of Askaban, setting the standard for what is the best. You essentially know what you're going to get, and you're either on board by now or you're not.

That said, the sixth and newest entry, Harry Potter and the Half-Blood Prince, is almost a whole other animal, a mixed bag of frustrations that in some places hints at a newfound greatness and in others just plain stinks. Directed by David Yates, who also sat behind the camera for 2007's Order of the Phoenix, it tackles one of the longest and more difficult of the novels. With Harry and friends firmly ensconced in their adolescence, teen angst is in ample supply. The book's author, J.K. Rowling, smartly advanced the tone of the books with the age of her characters, and this difficult dark before the storm proved the perfect time for her to delve into the twisted history of the series villain, he who should not be named, Lord Voldemort. He is played in the earlier movies by Ralph Fiennes, but Mr. Fiennes has no opportunity to appear this time around. It's the child version that is of concern here, Tom Riddle, seen at age 11 (Hero Fiennes-Tiffin, nephew of Ralph) and age 16 (Frank Dillane). Voldemort gets three scenes from his past...and that's it. Bye-bye to the rest of that stuff.

Which leaves us with what, exactly? Well, a lot of teenagers making moon eyes and kissing, which, I don't know, may be interesting if you're a teenager, but left me pretty bored. Or maybe it's not that teens are uninteresting, it's just they are written as such here, like Yates and writer Steve Kloves are relying on the fact that we know all of these characters and think we will already have a vested interest in who they are snogging, no need to flesh out the emotions. Ron Weasley (Rupert Grint) and Hermione Granger (Emma Watson) have broken up, but it makes their friendship uncomfortable, especially when he is pursued by Lavender Brown (Jessie Cave) and she by Cormac McLaggen (Freddie Stroma), the ditz and the jock, respectively. They are both such obvious types, there is really no doubt where they will end up on the romantic scrap heap, and the brief doubts that we are meant to have over whether Hermione and Harry (Daniel Radcliffe) will ever find love in each other's long gaze are not very potent, either. Harry clearly likes Ron's sister Ginny (Bonnie Wright), and I can't recall if her first boy ever has a line in the movie, so you can guess where he's going. Awww, there's Hermione crying in the hall after the dance. Where's Duckie when you need him?

All of this hormonal hoopla only serves to get in the way of the good stuff. Interwoven amidst the heavy sighs and chapped lips is a plot by the Death Eaters to remove their light magic competitors and clear the opposition for the return of their Dark Lord. Led by Bellatrix Lestrange (a delicious Helena Bonham Carter, still not getting enough screen time), and featuring an unholy pact between Snape (Alan Rickman) and the Malfoy family, these baddies have all of Hogwarts living in fear. The entire film exists within a literal cloud of doom. Everything is gray and ashen, and many of the old haunts are in ruins. For all appearances, evil is winning. Dumbledore (Michael Gambon) has plans of his own, however, and he lures Professor Horace Slughorn (Jim Broadbent) back to the school to try to get secret information out of him. Slughorn is a teacher who "collects" famous students the way an army general might collect medals. He once taught Voldemort, and Dumbledore banks on him wanting Harry's name on his resume. If Harry can get close, he might be able to extract Voldemort's secret from the old prof.

Jim Broadbent is the highlight of Harry Potter and the Half-Blood Prince. His portrayal of the besotted, forgetful Slughorn infuses just about every scene he is in with laughs. In the others, he's tugging the heart strings. Harry's mother, Lily (Geraldine Somerville), was one of his favorite pupils, and it's in her honor that the good things that get done do get done. While most of the rest of the cast has settled comfortably into their positions and don't really stretch themselves, Broadbent gets everything out of this one-off that he can.

One returning player that does stretch himself is David Yates. Despite the narrative confusion, the direction in Half-Blood Prince is some of the best in the series, and his energized style even rivals Cuarón's. I don't recall the effects ever being this dazzling. It may seem so because so much of the environment has been destroyed, and with all the noise and the busy details dialed down, little touches like the Weasley Twins' magic shop seem all the more clever for their singularity. For as much as the movie is weighed down by the dour storytelling, Yates consistently breaks free by sending his camera on flights of fancy, racing along with Bellatrix and her raiders or hiding in the shadows and peering through elaborate scenery to spy secrets. I loved that first bit at the Weasley home, where Ginny peers up the Escher-like staircase and Mother Weasley (Julie Walters), Ron, and Hermione all pop out at different levels. Yates pulls off similar magic throughout, right up to the climax in the clock tower, using secret entrances and hidden cubbies to emphasize the multiple layers of deception.

And, oh! What a climax we have! If you can hold your breath through all the tortured stares and hurt feelings, there is a good payoff. The mission that Harry and Dumbledore undertake is both scary and exciting, and it makes Harry Potter and the Half-Blood Prince mostly worth it. Up until then, I wouldn't necessarily call it a bad movie, but it is a slightly dull one, and as a whole, it feels more like a bridge to the final entry than it does a stand-alone motion picture. Had they maybe cut a half-hour of kissy-face out of it, and either left it a leaner picture or added in half an hour of Voldemort, we might have had something else entirely...but alas, as Potter fans have likely learned from the stories, we can't get by on what might have been. There is only what there is.

Jamie S. Rich is a novelist and comic book writer. He is best known for his collaborations with Joelle Jones, including the hardboiled crime comic book You Have Killed Me, the challenging romance 12 Reasons Why I Love Her, and the 2007 prose novel Have You Seen the Horizon Lately?, for which Jones did the cover. All three were published by Oni Press. His most recent projects include the futuristic romance A Boy and a Girl with Natalie Nourigat; Archer Coe and the Thousand Natural Shocks, a loopy crime tale drawn by Dan Christensen; and the horror miniseries Madame Frankenstein, a collaboration with Megan Levens. Follow Rich's blog at Confessions123.com.