“Origin” is one of the most ambitious movies in recent memory, spanning multiple centuries and continents as it attempts to untangle the roots of racism.

It’s also completely riveting. The thought-provoking drama (in theaters now) follows author Isabel Wilkerson (Aunjanue Ellis-Taylor) as she traverses the globe researching her 2020 book “Caste: The Origins of Our Discontents.” Much of the film is spent in libraries, living rooms and out in the field, as Isabel conducts interviews and searches for links between historical injustices.

Writer/director Ava DuVernay looked to journalism movies such as “Spotlight” and “She Said” as she aimed to make the grunt work compelling.

“Isabel is a capital-J journalist, so I wanted to lean into what the investigative process is like,” DuVernay says. “It’s about this genius pursuit of truth that only she can see and has to convince others of. We see this genius subgenre in a lot of films, but maybe not rendered in the body of a Black woman.”

'Origin' star Aunjanue Ellis-Taylor is 'still grappling with' the meaning of caste

In her book, Wilkerson posits that caste is an artificial social hierarchy determined at birth and used to subjugate or exploit other people. She believes the system is based on arbitrary differences between human beings, and that it's the very foundation of all the “isms”: racism, sexism, homophobia, antisemitism and Islamophobia.

“Her argument is that caste is the more effective way we should look at social divisions, in this country and around the world,” Ellis-Taylor says. The film explores how the Nazis were inspired by Jim Crow laws, and the ways that caste pervaded the segregated American South: “Confederate statues, lynchings, having to use separate water fountains – they were all employed to scare and control formerly enslaved people.”

Caste is a heady concept that "I'm still grappling with," Ellis-Taylor admits. "I take the book with me everywhere I go." DuVernay says that she saw “no cinematic potential” her first time reading “Caste.” But when she gave it a second look, “I just really leaned into my curiosity about trying to make these connections. I started to think, ‘Wow, this is information that people should know.’ “

Her way into the material wound up being Wilkerson, who spent hours with the filmmaker on Zoom sharing details about her life. The author’s personal story anchors the deeply emotional movie, as she struggles to move forward after losing her husband, mother and cousin in rapid succession. DuVernay beautifully captures the surreal nature of grief, and how it feels like “time is not moving in the same way.”

"Where you sit doesn't matter because you're not even really there," DuVernay says. “Grief is something we don’t face enough as Americans, so the considerations of how to dramatize grief really came from my own experience. All I could draw upon is what it felt like to me when I lost my father.”

Despite Oscar snubs, Ava DuVernay believes 'Origin' will 'find its way in time'

Even with strong reviews (81% fresh on survey site Rotten Tomatoes), “Origin” was shunned by major awards including last week’s Oscar nominations. DuVernay, whose past films “Selma” and “13th” were both Oscar-nominated, has lamented Ellis-Taylor's absence from the conversation: “I wish she had commercials and magazine covers and all the things that are arranged for the actresses we are supposed to pay attention to in the awards season,” DuVernay wrote earlier this month in a since-deleted Instagram post.

Ellis-Taylor, 54, received her first Oscar nod in 2022 for best supporting actress in “King Richard,” a major studio drama starring Will Smith and produced by Venus and Serena Williams. Campaigning for awards that season, “there was nothing that I wanted. There was no work to it, at least on my part, and I oddly assumed that’s just how it is,” Ellis-Taylor recalls.

But for an independent feature like “Origin" with limited marketing, she’s resorted to passing out flyers around Los Angeles to help spread the word. “What it came out of was my frustration with hearing constantly that nobody has seen the film and that nobody knows about it,” Ellis-Taylor says. “I don’t have $1 million to put a billboard up or do a commercial. But what I can do is hit the streets and I don’t have to wait for anybody else.”

DuVernay has similarly taken a grassroots approach to promoting the movie: sponsoring free tickets for more people to see it and traveling around the country on her own dime to host screenings. Celebrities such as Angelina Jolie, Regina King and Cher have also championed the project with events and social media posts in recent weeks.

Awards season “is a game and it’s a tough one,” DuVernay says. “Someone was reminding me that ‘Fight Club’ was completely dismissed when it came out, and now it’s seen as this iconic cinema classic. So many films have gone through that, so I believe this one will find its way in time.”