We solemnly swear that we are up to no good. One of the best parts of the Harry Potter movies (and the books for that matter) are the Weasley twins, Fred and George, played by real-world twin brothers James and Oliver Phelps.
While we won't go into Fred's tragic fate in Deathly Hallows (*sniff*), we will talk about how Prisoner of Azkaban director Alfonso Cuarón tweaked the third movie's script to make Fred and George seem like one seamless entity, something that J.K. Rowling did a lot in her books. In the scene where they give Harry (Daniel Radcliffe) the Marauder's Map (co-written by his father, James) so that he can sneak into Hogsmeade, they finish each other's s̶a̶n̶d̶w̶i̶c̶h̶e̶s̶ sentences, their rapid fire dialogue sounding as natural as can be.
As it turns out, the Phelps brothers do that in real life and Cuarón wanted to showcase it in the film.
“We’d done a few things earlier in the year with Alfonso when we met him, and he liked the way we always cut each other off,” Oliver told Entertainment Weekly. “We did that quite a bit, so he got the script slightly changed so Fred and George were always finishing each other’s lines off, which we ended up doing in the film.”
The Marauder's Map scene is Oliver's favorite sequence throughout the entire franchise because of the connection it had to his late grandfather, who passed away before Prisoner of Azkaban was released in theaters.
“Of all the scenes we did in all the eight films, that’s the one I treasure more than anything,” he said. “Because when we got the part, my grandfather started reading the books to try and understand what on earth we were doing, and he always said that scene was when you see our characters for the first time in their own element ... I still remember to this day calling my granddad from the hotel and telling him how it went and everything."