9. Professor Lupin’s Secret (The Prisoner Of Azkaban)
Harry’s first two Defence Against the Dark Arts teachers were far from ideal. One was in league with the Dark Lord, and the other was a fraudster.
Professor Lupin, on the other hand, is a competent teacher with a firm moral compass. Harry and his classmates take to him in their very first lesson. But like many Harry Potter characters, Lupin is much more than he appears to be.
Throughout the school year, he’s plagued by a mysterious, reoccurring illness, and Professor Snape has to cover some of his lessons. Only Hermione is able to figure out what’s happening, and she reveals the truth in the Shrieking Shack.
Whilst the Marauders’ backstory is thinned out in the movie, the unveiling of Lupin’s werewolf condition is still a great twist. It gives one of the most likeable characters a dark undertone that no one saw coming.
We then see the full extent of his condition later on, and witnessing this transformation is the most unsettling moment in the series so far. The music, the moonrise, and the grotesque movements come together to create a truly terrifying scene.