The film begins with a vivid dream sequence featuring a young Nat Turner (Tony Espinosa), who is led into the woods to meet a native tribe. The tribe's leader reveals that children with distinct birthmarks, like Nat's three vertical scars on his chest, are destined for significant purposes.
Set in Southampton County, Virginia, in 1809, Nat lives in enslavement alongside his mother, Nancy (Aunjanue Ellis), father Isaac (Dwight Henry), and grandmother Bridget (Esther Scott). They serve the Turner family, where Nat often plays with their young son Samuel (Armie Hammer). One day, while his mother Elizabeth (Penelope Ann Miller) calls him inside, Nat notices a book resting on the porch's rocking chair.
One fateful night, Isaac is caught pilfering food by a trio of white men led by Raymond Cobb (Jackie Earle Haley). In a tense confrontation, Isaac seizes Cobb's gun, and in the chaos, a man is fatally shot. Isaac manages to escape and returns to find Nat hidden in the woods, recognizing he must leave for safety. When Cobb and his accomplices come to inquire about Isaac's whereabouts, Nat remains silent while Nancy and Bridget insist they know nothing.
In conversation with Nancy while hanging laundry, Elizabeth discloses that Nat possesses the ability to read, which surprises his mother. Elizabeth kindly offers to teach him, introducing him to reading through the Bible. Nat later takes to the pulpit at church, captivating the congregation with his sermons.
With the passing of Benjamin Turner, Nat is absorbed into family labor in the fields. Time leaps to 1831, and Nat, now portrayed by Nate Parker (Nate Parker), shares a ride with Samuel as they pass a slave auction. Captivated by a woman named Cherry (Aja Naomi King), Nat persuades Samuel to purchase her for $275.
On their return home, Nat attempts to fetch a toy for a white boy, but this kindness leads to violence when the boy's father beats Nat for speaking to his wife. Samuel intervenes, promising retaliation if the father doesn't back off. Back at home, Nat has a rough encounter with Cherry, who lashes out at him, and later she is groomed to be presented to Samuel's sister.
Reverend Walthall (Mark Boone Junior) suggests that Nat embark on a preaching tour of local plantations, with Samuel's family set to benefit financially. As Nat builds a bond with Cherry, whose true name is Madison, the two marry in secret with Bridget officiating. Eventually, they welcome a daughter named Joanna into their lives.
During Nat's preaching journeys, he bears witness to the brutal treatment of slaves by their masters. Disturbing scenes unfold as he watches a man brutally torture a slave, and another sap a married woman's spirit. Following a horrific event where Cherry is assaulted by Cobb's men, Nat returns to find her badly injured in bed.
With his spirit ignited, Nat's sermons grow increasingly fervent, leading to a clash with Samuel when he refuses subservience. After a brutal punishment, Nat’s pent-up anger boils over, and he rallies fellow slaves to rise against their oppressors. The rebellion sees Nat attack Samuel fatally before unleashing chaos upon the community. They face a shocking retaliation as a mob seeks vengeance for the uprising, and in the ensuing violence, Nat engages in a fierce battle with Cobb, ultimately killing him.
The aftermath sees Nat being captured, and in a desperate act of bravery, he turns himself in to a furious mob, receiving a harsh beating before being detained at the gallows. Amidst a crowd of jeers and threats, he stands resolute. When asked for final words, he proclaims, “I’m ready,” before he is hanged, his last vision being Cherry appeared to him as an angel. The scene shifts to the young boy who had betrayed Nat, now grown up and fighting valiantly alongside fellow black soldiers in the civil war.
The film concludes with stark text revealing the brutal legacy of Nat Turner's 1831 rebellion, which lasted nearly 48 hours, resulting in over 60 white deaths and an even greater toll on the black community. Nat’s own body was treated with grotesque cruelty, flayed and dismembered, all to extinguish the enduring legacy of resistance.
