As “Harry Potter and the Half-Blood Prince” opens, Yates observes, “It is a very tense time in the wizarding world because Lord Voldemort has returned from hiding.”

Empowered by the return of the Dark Lord, the Death Eaters are attacking openly and at will, and even the Muggle world is not impervious to their reign of terror. As ominous dark clouds swirl over London, people look up, sensing an unfamiliar danger. Suddenly, three Death Eaters swoop out of the clouds and fly through the city, leaving a path of destruction in their wake. Unseen by the naked eye, they spiral around London’s Millennium Bridge, causing it to buckle and then collapse, sending pedestrians running for their lives.

Heyman relates, “The anarchy wrought by Voldemort’s followers that has begun to undermine the wizarding world is now washing over into the Muggle world.”

We catch up with Harry Potter in a train station coffee shop, with one eye on the Daily Prophet story about the bridge attack and the other on the pretty waitress who needs no coaxing to tell him what time her shift ends. But before Harry can follow through on his date, Professor Dumbledore appears on the station platform and literally whisks him away on a mysterious mission.

Barron notes, “Harry has no idea where they are going or what Dumbledore is expecting of him when they get there. But he knows that if Dumbledore has asked him to do something, it must be important, so Harry doesn’t ask questions; he just goes with it.”

Reprising the role of the venerable Professor Dumbledore, Michael Gambon remarks, “The relationship between Harry and Dumbledore in this film goes beyond headmaster and student. As Harry has grown from a schoolboy into an intelligent young man, their relationship has grown into more of a close friendship.”

Heyman elaborates, “What we’re seeing in this film is Dumbledore preparing Harry to carry the mantle. As we have seen in the past, he is again a father figure to Harry, but no longer is Harry the child he was when the stories began. He is a young man and so Dumbledore deals with him on somewhat more equal terms. But we still see Dumbledore guiding him and helping him prepare for the future—a future that inevitably involves a confrontation with Voldemort.”

Arriving in the village of Budleigh Babberton, Dumbledore takes Harry to the home of a Muggle family, which appears to have been ransacked. Though the house seems uninhabited, it doesn’t take long before Dumbledore uncovers an interloper hiding amidst the mess: Horace Slughorn. Once a popular Potions professor at Hogwarts, Horace had retired years earlier, taking with him memories of his best students, including one Tom Riddle, who showed a particular interest in the Dark Arts.

When Voldemort was believed dead, memories of the boy he once was seemed of little consequence. But now that Voldemort is proven to be very much alive, the history of Tom Riddle’s transformation into the Dark Lord could hold the clues to his power. And Dumbledore is sure that Horace Slughorn remembers Tom Riddle all too well because Tom had been one of his star pupils.

Barron explains, “Slughorn is a social climber. He loves to know the best people and to name drop the celebrities of their world. He’s immensely proud that many of them had passed through his classes when he was a professor at Hogwarts, and that he can still call on them. It appeals to his vanity.”

Veteran actor Jim Broadbent, who stars as Horace Slughorn, describes his role as “a fascinating and rich character. He’s passionate about his work and incredibly knowledgeable as a Potions master. He’s top-notch, but he’s also flawed. There is a dark secret in his past that weighs heavily on him. He has gone to great lengths never to reveal it…and that’s where Harry Potter comes in. Harry is the bait for Slughorn to return to Hogwarts.”

Basking in the reflected glory of his most prized students, Slughorn keeps all their photographs on a shelf where he can point to them with pride. And Dumbledore has no doubt that the famous Harry Potter—the Chosen One himself—would be what he calls “the crowning jewel” of that collection.

Nevertheless, Slughorn tries his best not to appear too overeager: “He insists on a bigger office and a large pay raise,” Broadbent asserts.

Slughorn’s demands for a better office were the marching orders for production designer Stuart Craig and his team. “That was the directive: to give him a very substantial office,” says Craig. “We wanted it to be rich and dramatic and have a strong architectural form. It has a huge fireplace and a splendid terrace with a view of the mountains. What it needed most of all was a sense of theatricality, as befitting the character.”

“The set was magnificent. I’m glad Horace held out for better digs,” Broadbent smiles. “It was wonderful.”

Costume designer Jany Temime also had fun creating the wardrobe for the character she describes as “a bit of a dandy. Professor Slughorn is a rather eccentric English gentleman, who loves good wine, good food, good company and, of course, good clothes. We dressed him in tweed suits with big patterns and little bowties and he also has a lovely velour suit that he wears for his Christmas party. He looks extremely grand. At the same time, he has not been working for some time and his clothes have seen better days, so while his clothes are beautiful, there are a few buttons hanging, and so forth.”

Temime discloses that she also added something to help Broadbent be the measure of the man, so to speak. “We had to pad him because the character is much rounder than Jim is in reality. When we saw him for the first costume fitting, he came in as Jim Broadbent and left as Professor Slughorn. It was a pleasure to work with him.”

Yates agrees. “Jim is a delight. He has a tremendous capacity for both comedy and pathos and I knew he would bring so much to the table. Slughorn is a very colorful character, and Jim wasn’t afraid to take risks and try things that were heightened but still felt anchored in truth. Slughorn is also a real snob; he’s only interested in talking to the most important person in the room and ignores everybody else. I thought Jim could have some fun with that and he did.”

“We felt incredibly fortunate to have an actor of Jim’s caliber join our Harry Potter family,” adds Heyman. “From the very first film, we have been so honored by the depth of the acting talent in our casts, and he is one of the best. He was a warm and generous presence on the set.”