In addition to his nifty new Adam’s apple, pubescent boy wizard Harry Potter (Daniel Radcliffe) comes equipped with a veritable arsenal of supernatural goodies in “Harry Potter and the Prisoner of Azkaban,” including a time travel amulet, a magic locater map and a majestic winged beast that he rides like Funny Cide over the cloud tops.

Unfortunately, Harry's most pressing need goes unmet — specifically, a good family practice attorney.

As always, this “Harry Potter” installment — the third in a series based on J.K. Rowling’s phenomenally successful children’s books — is built around Harry’s quest for the truth regarding his dead parents, murdered many years ago by the sinister Lord Valdemort. Just as predictably, Harry is stymied by a tight-lipped adult faculty that inexplicably refuses to surrender its secrets.

Ultimately, this familiar cycle of conceal and reveal grows tiresome. Two hours in, you wish Harry would hire Alan Dershowitz, cite the Freedom of Information Act and take those cagey stiffs at Hogwarts to court. Anything to give this floundering series a little buoyancy.

Granted, there’s more psychological texture here than in previous “Potter” offerings, due chiefly to the fact that it was directed by Alfonso Cuaron, who also helmed (please excuse the sarcasm) that other acclaimed kids’ movie, “Y Tu Mamá También.”

Assuming command of the franchise from the competent but unremarkably one-note Chris Columbus, Cuaron brings with him a moodier, more baroque visual palette to complement the story’s portentous themes. It’s like the difference between Mother Goose and Brothers Grimm. Trained and educated in Mexico, Cuaron is a filmmaker who revels in details, one who can harness the sensuous energy from, say, the image of a shriveled sunflower and use it to enliven an entire scene.

To be sure, something rotten is afoot at Hogwarts, the school for neophyte wizards and witches where Harry — along with pals Ron (Rupert Grint) and Hermione (Emma Watson) — is entering his third year. Now permanently cut off from his abusive, non-magical relatives (in retaliation for an insult against his parents, he turned his uncle's insufferable sister into a human balloon), Harry finds himself facing a more terrifying menace: Sirius Black, the dangerous fugitive wizard who betrayed his parents and orchestrated their death. Played by ‘‘Sid and Nancy’’ nutcase Gary Oldman — who is far too under-used in this movie — Black has escaped from prison and is at large, purportedly hell-bent on killing Harry, too.

Per tradition, Harry is forced to don his invisibility cloak and skulk around to wrest bits of information away from his secretive guardians, but does find an ally in Professor Lupin (David Thewlis from “The Island of Dr. Moreau”), his Defense Against the Dark Arts teacher. Once close to Harry’s parents, Lupin confides in Harry his fondness for the deceased Potters and admits that Harry's father was a bit of a rakehell in his youth.

According to fans in the know, this genealogical detail comes to bloom in later ‘‘Potter’’ volumes; explaining, for instance, why Professor Snape (Alan Rickman) harbors such a blistering hatred of young Harry.

However, in the here and now, more questions are posed than answered, including the central mystery of why Harry's parents were murdered in the first place. In the first two movies, the vagaries were tolerable. Now, in the third installment, typically the termination point for most sagas, the series' unrelenting air of enigma has officially been upgraded to tedious.

It matters little that the elusiveness of the "Potter" stories is by design — Rowling clearly envisioned Hogwarts to reflect the adult world through a child's eyes: nurturing yet threatening, scholarly yet enigmatic, rife with horrible, wonderful secrets and half-understood rules. Even Dumbledore, the kindly headmaster played by Michael Gambon (‘‘Gosford Park’’), stepping in for the late Richard Harris, seems only tangentially interested in Harry's well-being. Harry’s new teacher, the tea leaf-reading Professor Trelawney (Emma Thompson), is a near-sighted gypsy who fills his head with paranoid thoughts of death and doom. Put it this way: under the No Child Left Behind system, Hogwarts would have had its accreditation yanked years ago.

All of which is fine for the rank-and-file ‘‘Harry’’ faithful, who are invested enough in the characters — i.e. ‘‘Will Ron ever hook up with Hermione?’’ — that they can tolerate the ineffectual plotting and snails-clip conflict resolution.

The rest of us must find our delights in the movie's bodacious special effects (more seamless than before, including a great quidditch scene), lush production design and generous imagination. Until "Harry Potter and the Goblet of Fire" comes out sometime next year under the direction of Mike Newell ("Four Weddings and a Funeral"), any deeper or meaningful revelations about Harry and his background is up to the courts.