Warner Bros. offers the following plot summary of the new movie: Emboldened by the return of Lord Voldemort, the Death Eaters are wreaking havoc in both the Muggle and wizarding worlds and Hogwarts is no longer the safe haven it once was. Harry suspects that new dangers may lie within the castle, but Dumbledore is more intent upon preparing him for the final battle that he knows is fast approaching. He needs Harry to help him uncover a vital key to unlocking Voldemort's defenses, critical information known only to Hogwarts' former Potions Professor, Horace Slughorn. With that in mind, Dumbledore manipulates his old colleague into returning to his previous post with promises of more money, a bigger office, and the chance to teach the famous Harry Potter.
Meanwhile, the students are under attack from a very different adversary as teenage hormones rage across the ramparts. Harry's long friendship with Ginny Weasley is growing into something deeper, but standing in the way is Ginny's boyfriend, Dean Thomas, not to mention her big brother Ron. But Ron's got romantic entanglements of his own to worry about, with Lavender Brown lavishing her affections on him, leaving Hermione simmering with jealousy yet determined not to show her feelings. And then a box of love potion-laced chocolates ends up in the wrong hands and changes everything.
As romance blossoms, one student remains aloof with far more important matters on his mind. He is determined to make his mark, albeit a dark one. Love is in the air, but tragedy lies ahead and Hogwarts may never be the same again.
"I admired this Harry Potter. It opens and closes well, and has wondrous art design and cinematography as always, only more so. The middle passages spin their wheels somewhat, hurrying about to establish events and places not absolutely essential. But those scenes may be especially valued by devoted students of the Potter saga. They may also be the only ones who fully understand them; ordinary viewers may be excused for feeling baffled some of the time." Roger Ebert
"Harry is better than ever, a triumph of visual wonder and emotional storytelling. All the actors excel at pulling us into the film's mysteries. Radcliffe's growing maturity as Harry gives the role a touching gravity. His scenes with Gambon, superb as Dumbledore, exude ferocity and feeling, notably when they seek a horcrux, where part of the Dark Lord's soul resides, on a lake teeming with undead corpses. It's scary, resonant magic, poetically shot by the illustrious Bruno Delbonnel (Amelie). The shadows, and the dangers lurking within, have always drawn me deepest into Potter world. Newcomers shouldn't worry about playing catchup. Getting lost in the hypnotic Half-Blood Prince is what gives the movie its haunting power." Rolling Stone
"Are we there yet? Well, not quite. Harry Potter and the Half-Blood Prince, the latest big-screen iteration of the global phenomenon, is merely the sixth chapter in a now eight-part series that, much like its young hero, played by Daniel Radcliffe, has begun to show signs of stress around the edges, a bit of fatigue, or maybe that's just my gnawing impatience." NY Times
"Audiences are bound for adventure with a well-crafted film that is faithful to its rambunctious book and deeply attached to its actors." LA Times
"'Half-Blood Prince' is witty, spectacular and one of the best. Though Half-Blood Prince is one of the series's best, with spectacular effects, nuanced performances and witty dialogue, its dialed-down adaptation of Rowling's conclusion ends what might have been a masterful work with a measure of disappointment." USA Today
"Half-Blood Prince encompasses important plot developments involving both love and death. But the story is, still and all, only a pause, deferring an intensely anticipated conclusion. And it's in that exquisite place of action and waiting that this elegantly balanced production emerges as a model adaptation. By now, as played with utmost loyalty to the cause by some of Britain's most illustrious actors, the supporting characters are as familiar as the population of Homer Simpson's neighborhood (and that's a great compliment). Yet with a big assist from cinematographer Bruno Delbonnel -- a Potter newbie who memorably shot Amélie and Across the Universe -- the filmmakers have found a way to refresh our eyes and enhance our appreciation for this rich, amazing creation." Entertainment Weekly