See Sydney Sweeney, Amanda Seyfried in New Movie (Exclusive)

Sydney Sweeney and Amanda Seyfried are full of secrets in PEOPLE’s exclusive first look at The Housemaid.

Their chemistry is “simply through the roof,” says director Paul Feig, who is also behind the A Simple Favor films. “They are both such powerful talents and work so well off each other that you very quickly get sucked into their onscreen world.”

An adaptation of Freida McFadden’s bestseller, The Housemaid stars Sweeney as Millie, a woman trying to escape her past and restart her life. Millie lands a job as a live-in housemaid for the seemingly perfect, wealthy Winchesters, Nina and Andrew, played by Seyfried and It Ends With Us star Brandon Sklenar.

Things take a turn when the gig spirals, thrusting Millie into a dangerous dynamic. A logline for the film promises a “seductive game of secrets, scandal and power” behind the closed doors of the Winchesters’ mansion.

“The film captures everything fans loved about the book — the secrets, the tension and the twists,” says Seyfried, 39. “We can’t wait for audiences to immerse themselves in the experience.”

Sweeney, 27, says Millie is exactly “the type of character I love to play: complex, strong and with a little something up her sleeve.” The Euphoria star adds, “I can’t wait for fans to see how hard we all worked to bring The Housemaid to life.”

Who will audiences side with? Feig, 62, teases that Millie is “someone we invest in immediately as she walks into what to her is a very foreign world of wealth and high expectations,” whereas Nina is “a portrait of unpredictability and extremes.”

“It’s thrilling to see their interplay as the Millie-Nina relationship changes over the course of the film,” he says.

Behind the scenes, Sweeney and Seyfried were “true joys to work with,” says the filmmaker.

“They are both up for anything, and we had so much fun playing with all the twists and turns that the story takes these characters through,” says Feig. “They both slipped into these challenging roles effortlessly and took full ownership of them. We couldn’t have had a better time together making this movie.”

The cast also includes Michele Morrone as the watchful groundskeeper Enzo and Elizabeth Perkins as Andrew’s hard-to-please mother.

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From a script by Rebecca Sonnenshine, the film is a “faithful interpretation” of the book, says Feig — “but with a good number of added surprises along the way.”

“And no, I’m not teasing any of the surprises,” he says. “They must be seen to be believed.”

He calls the big-screen adaptation “shocking, delicious and fun,” adding: “The Housemaid is pure entertainment – a sexy and surprising rollercoaster ride of a movie that will keep audiences on the edge of their seats. This movie is the kind of insane fun that you’ll want to watch over and over this holiday season.”

“So bring your friends and wear your pearls because you’ll definitely be clutching them!”

The Housemaid is in theaters Dec. 19.