But like the books, the third film is a lot darker than the others.
"It's a lot scarier than the first two," Chris, from Norfolk, said. "There's a lot of scary stuff happening."
Chris told the BBC's Norfolk website that he was a bit nervous about acting alongside all the famous people in the Potter films, like Dame Maggie Smith and Alan Rickman.
"It was quite daunting to start with but they're just normal people I've discovered. Amazingly talented people. It's wonderful to work with them."