By Adam B. Vary
Updated November 16, 2010 at 02:15 PM EST

In our week-long look back atthe Harry Potter film franchise in anticipation of Harry Potter and the Deathly Hallows–Part 1, perhaps no film has proven quite as important to the series and as much a bellwether of what was to come as Harry Potter and the Prisoner of Azkaban. Yes, the first two films had grossed $967 million and $866 million worldwide respectively, but their director, Chris Columbus, had been tarred as too slavish to J.K. Rowling’s books, and not as cinematically, well, magical as one might hope. Plus, as Jeff Jensen put it in his June 11, 2004 cover story, “Azkaban introduces adolescence — awkward, angry, hormonally charged — into the thematic mix.” The man held responsible for selling out Harry’s parents to Voldemort, Sirius Black (Gary Oldman), had escaped Azkaban prison; soul-sucking, wraith-like Dementors were on the hunt to recapture him, and had little regard for playing nice with whoever got in their way. This wasn’t a sweet children’s fantasy anymore. The question, really, was simple: Were the Harry Potter films going to continue to play it safe and hazard feeling staid and boring? Or would they shake things up, gamble with taking some bold creative risks, and perhaps even break ranks with Rowling’s books? Would they, could they, stand on their own as films in their own right?

Enter director Alfonso Cuarón. At the time best known as the director of 2001’s racy, adult drama Y tu mamá también, he was a surprising choice to take the reigns of a massive Hollywood family film franchise. But that was pretty much the point. “Alfonso is basically a teenager himself,” said Potter producer David Heyman. “Mischievous. Naughty. Funny. Loves to shake things up.”

And that he did, too: At his very first lunch with stars Daniel Radcliffe, Emma Watson, and Rupert Grint as their new director, Cuarón asked each of them to pen an essay about their characters. Radcliffe was irked at first: “I thought, ‘Who is this man, coming in here and giving us homework?'” As it turned out, the exercise proved its purpose. Watson turned in an 11-page manifesto on Hermione, and in the process discovered perhaps there wasn’t much daylight between her and her role. “It was the first time I had ever thought about Hermione’s character in such detail,” she said. Radcliffe’s single-page essay surprisingly focused on Harry’s arrogance and anger, which proved prophetic after Rowling’s Harry Potter and the Order of the Phoenix — featuring quite an arrogant and angry Harry — was released during the third film’s production. And as for Grint, well, he didn’t so much do an essay, much as Ron would have done (or, rather, wouldn’t have done).

Cuarón continued to shake things up well into production. He relocated Hogwarts castle to the Scottish Highlands, forcing production delays due to bad weather. He collaborated with screenwriter Steve Kloves on inventing scenes whole cloth, like Harry’s solo joyride on a majestic Hippogriff (part horse, part eagle). He encouraged actor Michael Gambon, who replaced the late Richard Harris as Hogwarts Headmaster Albus Dumbledore, to embrace the character’s eccentric sensibility, dressing him more like a magical hippie than the classic wizard from the first two films. He asked for longer, more complicated takes, challenging his young actors to stretch past their limitations. “Sometimes, it took two weeks for me just to get one shot right,” said Radcliffe. When the title star approached Cuarón for help in nailing a particularly demanding monologue railing against Sirius Black, instead of simply giving him suggestions for facial expressions like Columbus would have, Cuarón talked Radcliffe through Harry’s emotional life. Then he said, figure this out for yourself. “I’ll forever be in his debt,” Radcliffe raved. “It basically affected the way I approached everything after that.”

The result: In his B+ review, EW critic Owen Gleiberman called The Prisoner of Azkaban “the first movie in the series with fear and wonder in its bones, and genuine fun, too.” He praised Radcliffe as “leaner, more handsome, and bolder than before,” and commended Cuarón’s “breathless visual and dramatic flow…shot in spooky gradations of silver and shadow. The whole movie zips along with a matter-of-fact cleverness that stays a step ahead of you….Cuarón…has gotten Rowling’s spirit on screen.”

Indeed, while The Prisoner of Azkaban is the lowest grossing of the Potter films, bringing in “just” $795 million worldwide, it remains to this day many fans’ absolute favorite of the series. I can remember seeing the film on opening weekend with a crew of fellow Potter-heads, and all of us exiting the theater with the slightly dizzy feeling that we’d just seen something, well, magical. That’s a terrific sensation when it’s caused by just one, standalone film. But knowing that a Harry Potter movie could truly live and breathe as its own experience — honoring Rowling’s spirit while not beholden to her every word — meant the prospect of revisiting the world of Harry Potter four more times that much more exhilarating.

How does Azkaban stack up for you? Is it still your favorite Potter film, or have The Goblet of Fire, The Order of the Phoenix, or The Half-Blood Prince usurped it? (Or The Sorcerer’s Stone or The Chamber of Secrets, for that matter?) And how much would you pay to see what Emma Watson and Daniel Radcliffe wrote in those essays Alfonso Cuarón made them write?

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