Note: This post contains spoilers from the film “Get Out.” 

Comedian Jordan Peele’s “Get Out” continues to perform well after topping the box office in its opening weekend and boasts a near perfect 99 percent rating on Rotten Tomatoes. But it’s not just Peele’s innovative and razor-sharp screenplay that makes the film such a success. “Get Out” is also especially well cast.

The thriller follows Chris Washington (Daniel Kaluuya), a black man who finds himself in a terrifying situation while accompanying white girlfriend Rose Armitage (Allison Williams) to her family’s home, where he meets her parents for the first time.

The film is groundbreaking in a number of ways. It’s about racism, which hasn’t been the focus of many horror films, although racial hatred is downright terrifying. And Peele focuses on a type of racism that isn’t usually dissected on screen. Rose’s parents are East Coast liberals who over-enthusiastically welcome Chris to their home before revealing a sinister plan. “Get Out” is also a subversive response to the horror genre, in which black men are usually supporting and expendable characters — not protagonists.

Kaluuya (“Sicario”) is British and relatively new to American audiences. Williams, of “Girls” fame, is more recognizable, but this is her first major movie role.

In 2011, Kaluuya starred in an episode of Charlie Brooker’s anthology series “Black Mirror,” known for its often unsettling social commentary about technology’s ever-increasing presence in our lives. The episode, titled “Fifteen Million Merits,” takes place in a dystopian future where Kaluuya’s character rebels (or attempts to) against a system that places value on reality competition shows and virtual advertising.

“It kind of made me feel how ‘Black Mirror’ made me feel when I read it,” Kaluuya told Vulture of reading Peele’s screenplay. And while “Get Out” is very much about racism in America, Kaluuya has said he can relate. The 27-year-old actor sued London’s Metropolitan Police in 2013 after he was pinned down and stripped search during an arrest he said was the result of racial profiling.

Peele told GQ that the most important aspect in casting the role of Chris “was having an actor who related to the isolation of being the only black person in a given space.”

“Only a black guy could write this, only someone that lives this,” Kaluuya told Vulture. “I’ve been to so many parties in England and in America that’s exactly like that, where you’re kind of like seen as Other. When you’re just living your life, and you have to adopt the Other in order to understand and navigate the society. That’s what I find really cool about it.”

In a recent interview with The Washington Post, Peele said Kaluuya was “exactly how I pictured Chris.” But when it comes to Rose, Peele said Williams helped the “Girls” star character “evolve into what she is and to who she is.” (note: a couple of spoilers ahead).

“My original take on the character was that she was a little bit messier, a little bit more ragged in a way — that she was sort of rebelling against the more pristine allure of her parents” Peele said. Rose takes a terrifying turn in the film, but she keeps her composure throughout, which makes the character even scarier. “Allison’s natural allure is that she is so precise, cool, smart and put together,” Peele added.

One scene in the film captures this perfectly. After Chris discovers that Rose and her family have kidnapped him, Rose sits calmly in her bedroom, eating Froot Loops and drinking milk through a straw while doing an Internet search for NCAA prospects and listening to “(I’ve Had) The Time of My Life,” from the 1987 film “Dirty Dancing.” The scene, which Peele said he wrote just a few days before filming it, is equal parts hilarious and chilling. Somehow, Williams manages to look deranged with nary a hair out of place.

It might seem strange for Williams to go from Lena Dunham’s HBO show, which has received criticism for its lack of diversity, to a film that makes a powerful statement about systemic racism. But her connection to the privileged characters on “Girls” actually makes her perfect for the role, especially when paired with her Ivy League education (she graduated from Yale). “She felt cosmopolitan but also undeniably Caucasian,” Peele told Business Insider.

Bradley Whitford, who plays Rose’s purportedly Obama-loving father, brings a similar appeal. Whitford is probably best known for his Emmy-winning role as Josh Lyman on “The West Wing,” about a left-wing president and his administration. He so fits the persona of a privileged but politically well-meaning white person that “Saturday Night Live” recently imagined him starring in a movie about a Republican “patriot who put country over party” and stood up to President Trump.

Another familiar figure is Keith Stanfield, who has a small but memorable role as a Brooklyn man kidnapped by the Armitages. Stanfield is a scene-stealer in Donald Glover’s buzzed-about FX dramedy  “Atlanta,” where his character definitely knows how to fist bump. Given the buzz around “Atlanta,” which recently won the Golden Globe for best TV comedy series, Stanfield’s role is especially well-timed.

If “Get Out” has a breakout star, it is Lil Rel Howery (“The Carmichael Show”), who plays Chris’s friend Rod, a Transportation Security Administration agent. Rod is suspicious of the Armitages from the very beginning of the film and ends up helping Chris escape from the family’s estate. Howery provides comic relief through phone conversations with Chris and his fervent efforts to alert authorities to his friend’s kidnapping.

“Rod is basically everyone in the theater who’s screaming at the screen,” Howery told the New York Times. “A character like that in a horror film is just genius.”