There is a method to Moody’s madness, though his irreverent brand of tough love often terrifies his students and draws criticism from his peers. “What appealed to me about the character,” says Gleeson thoughtfully, “is that he reminds me of some of my old teachers. He has no time for book learning. He wants to show these young men and women what they’re up against – evil exists and they better know what they’re getting themselves into. He’s a one-man initiation ceremony, a walking rite-of-passage. He doesn’t believe in treading lightly with Harry or the other students because that won’t prepare them for the real world.”

“It’s quite hard to play someone who is is the essence of evil,” muses Ralph Fiennes. “In my discussions with Mike about the character, we talked about giving Voldemort human qualities, because to just play ‘evil’ is really impossible. ‘Evil’ is often conveyed through gnashing of teeth and a lot of spit. I wanted my portrayal of Voldemort to be deeply, truly evil. That comes from fear, frustration and unhappiness. Voldemort was a rejected child. He had a very unhappy childhood, and that’s where his anger, jealousy and hatred began to fester.”

“Mike was very keen to explore Voldemort’s unexpected mood swings, his explosive rage,” Fiennes says. “There are moments when anger spits out of him at Harry and other moments when he can be almost pleasant. You never quite know what he’s going to do.

“People are incredibly scary when they’re charming but you suspect they might suddenly do something very violent,” he continues. “If you sit across the table from someone who offers you a glass of wine and a present, but you know that he stabbed his wife to death, it’s quite unnerving.”