But where Origin stands out is in its mix of theory and emotion. Isabel’s relationship with her husband Brett is an aspect of our protagonist’s romantic life but also her political one. When he suddenly passes away, Isabel is helped to process what has happened by her study of endogamy – the custom of marrying only within the limits of one’s own group. Her research allows her to both mourn and celebrate him as someone, by contrast, who defied the US caste system through love and understanding. It is a simple yet powerful demonstration of how educating oneself historically and sociologically can help nourish the soul and clarify personal struggles.
The film is shot with a richly coloured, textured and timeless-looking film grain, only adding to its feeling of tangible literary importance. Where it occasionally falters is with notes of over-dramatisation that ring hollow, detracting from the otherwise refined storytelling. Scenes where Isabel is lying despairingly on a bed of autumn leaves, or is filmed interacting with figures of the past through abstract sequences – “you are going to be fine”, she tells one young black boy barred from entering a whites-only pool – feel somewhat jarring when placed alongside real recreations of horrifying events, such as black slaves being transported from the hull of ships from Africa to the US, or the separation of mothers and children at concentration camps during the Holocaust.
“It happened, therefore it can happen again” – so goes the quote by Holocaust survivor Primo Levi, who is invoked within the film at a museum Isabel visits in Germany. If the Nazis were inspired by American methods of enslavement, as we learn in one scene, then future atrocities could be put in motion in the spirit of discrimination that is being perpetrated around the world today. Exploring this terrible framework, DuVernay’s film unfolds with unpreaching clarity and fierce focus, full of heart and vibrant intent.
★★★★☆
If you liked this story, sign up for the weekly bbc.com features newsletter, called The Essential List. A handpicked selection of stories from BBC Future, Culture, Worklife and Travel, delivered to your inbox every Friday.
If you would like to comment on this story or anything else you have seen on BBC Culture, head over to our Facebook page or message us on Twitter.