SummaryDorchester County, Maryland. 1849. Araminta “Minty” Ross (Cynthia Erivo) is a slave at the Brodess plantation who prays that someday she will be able to escape her circumstances and make a better life for her family. When slaveholder and patriarch Edward Brodess dies suddenly, Minty finds herself facing a terrible fate—she’s to be sold to new owners in the South, never to see her loved ones again. After experiencing a powerful premonition, she realizes there is only one course of action left to her. She needs to run. But leaving behind the only home she’s ever known comes with great peril. She’ll need to journey alone through miles of wilderness with only God and the North Star to guide her, pursued at every turn by Brodess’ vengeful son Gideon (Joe Alwyn).
Miraculously, “Minty” reaches the Pennsylvania border, crossing into freedom and traveling onward to Philadelphia, where she meets William Still (Leslie Odom Jr.) at the Pennsylvania Anti-Slavery Society. There, she chooses a new name, Harriet Tubman, and begins to establish roots as a working woman with the assistance of the entrepreneurial Marie Buchanon (Janelle Monáe). But Harriet can’t reconcile having her newfound freedom while so many remain behind. Harriet resolves to rescue her beloved husband, John Tubman (Zackary Momoh). Although John is technically a free man, as an African-American in Maryland, he remains in constant danger.
Disguising her identity, Harriet bravely returns to the Brodess plantation to bring John back home with her—but learns the devastating news that he has moved on after her departure, believing that she died during her escape to freedom. Nevertheless, Harriet, believing that she is called by God to serve a higher purpose, saves the lives of her other family members. Soon, she is a full-fledged conductor on the Underground Railroad—a liberator known as Moses, secretly helping runaway slaves reach the promised land.