Amanda Seyfried wants fans to go into The Housemaid movie without having read the source material. "Do not read it until you've seen the movie," Seyfried, 40, told Us Weekly exclusively ahead of the film's release. "Then it will ruin the twists for you." Seyfried recalled seeing a screening of The Housemaid "a couple of months ago" with a friend who had "no idea" what was going to happen - despite making some guesses. "This is exactly what we needed, especially around the holidays," Seyfried told Us of the thriller. "Do you know what I mean?" Sydney Sweeney and Amanda Seyfried Stun at NYC 'The Housemaid' Premiere The Housemaid, based on the book of the same name written by Freida McFadden, stars Seyfried as Nina Winchester, who hires a woman named Millie (Sydney Sweeney) as her live-in housekeeper. Millie is quick to find out that the seemingly perfect house she was just hired to clean isn't what she expected. Seyfried revealed during an appearance on the "Bookmarked" podcast earlier this week that the entire production had "the support" of McFadden as they brought the story to life on the big screen. "We felt empowered because we had her blessing," Seyfried said during the Tuesday, December 16, episode, noting that director Paul Feig helped as well. "You know, this movie is going to be special and surprising, even for the book lover. I almost feel like I need to read the book again." Courtesy Everett Collection Seyfried said that she didn't actually dive into the world of The Housemaid - which is a three-book series, plus one novella - until being cast as Nina. But it was a "privilege" for the actress to read the script because Nina is unlike any character she's ever played before. "It is the most fun role I've ever played, and it's probably not gonna happen for a long time," she said. Without giving too much away, Seyfried explained that she's "playing somebody who's playing somebody." She credited director Feig for offering "the space" to push her limits. "I got to explore rage in a way that I never had - very therapeutic - and watching it back, necessary," Seyfried added. Sydney Sweeney Reflects on Playing a Morally Questionable Character Seyfried explained that the movie as a whole was a "therapeutic" experience. "I channeled one of my fears in life. One of the things that I really struggle with when I'm with people - working with people, or having to be near people - who are unpredictable and hot and cold," she said. "This is who Nina is when you meet her. It was really, really fun and interesting to channel what I fear most. Try to find the scariest pieces of that and portray them." When it came to understanding Nina, the actress focused on one specific part of the character. "Obviously, I have to relate to a lot of things, but I think I relate to the fact that she's just had enough," Seyfried said. "She has to play one last part in order to find her destiny." The Housemaid hits theaters on Friday, December 19.