Blair Underwood (American Crime Story), Victoria Pedretti (You), Isha Blaaker (The Flight Attendant) and Finn Wittrock (Ratched) are among the final major additions to Academy Award nominee Ava DuVernay’s latest film Caste: The Origins of Our Discontents, based on the bestseller of the same name by Pulitzer Prize winner Isabel Wilkerson.

Others rounding out the ensemble led by Oscar nom Aunjanue Ellis, are Leonardo Nam (Westworld), Donna Mills (Nope) and Emily Yancy (Sharp Objects).

While the plot of Caste hasn’t yet been released, the work of nonfiction hailed by The New York Times as “an instant American classic” is said to examine the little-known system of hierarchy that has shaped America.

Caste will also star Vera Farmiga, Niecy Nash, Nick Offerman, Jon Bernthal, Audra McDonald and Connie Nielsen, as previously announced. DuVernay is directing from her own script, also producing alongside veteran collaborator Paul Garnes (Selma, Middle of Nowhere) of Array Filmworks.

Underwood comes to Caste after collaborating with DuVernay on her Emmy-winning Netflix limited series, When They See Us. The actor’s numerous film and TV credits also include Netflix’s Self Made: Inspired by the Life of Madam C.J. Walker, as well as the upcoming series Three Women based on the same-name novel by Lisa Taddeo, which recently moved from Showtime to Starz. He landed a Tony Award nomination for his lead role in the Kenny Leon-directed Broadway production of A Soldier’s Play in 2020.

Pedretti is best known for roles on Netflix’s series You, The Haunting of Hill House and The Haunting of Bly Manor. Notable feature credits include Josephine Decker’s Shirley and Quentin Tarantino’s Once Upon a Time in Hollywood.

Blaaker is best known for roles on HBO Max’s The Flight Attendant and Starz’s Run the World.

Wittrock is a 2x Emmy nominee for The Assassination of Gianni Versace: American Crime Story and American Horror Story who has also been seen on series like Ratched and Masters of Sex. Notable film credits include Judy, The Last Black Man in San Francisco, If Beale Street Could Talk, Landline, La La Land, The Big Short and Unbroken.