From a cinematic point of view, "Harriet," the new biopic of Harriet Tubman, is not the best movie you’ll see this year. But the story of Tubman — an American hero who escaped slavery, then risked her life again and again, leading roughly 70 enslaved people to freedom on the Underground Railroad — still feels like essential viewing.


Director Kasi Lemmons creates a viscerally evocative picture of the horrors of slavery, emphasizing from the beginning the way wealthy white plantation owners systematically designed the ugly institution to break the bodies, souls and familial bonds of the African Americans they forced into bondage. At an Austin Film Festival screening on Oct. 25, audience members audibly gasped at some acts of unfathomable cruelty portrayed in the film.


As a young girl, Tubman was brutally beaten. She suffered a head injury that caused a lifetime of fainting spells and hallucinations that she came to believe were visions from God. Lemmons positions Tubman as an American Joan of Arc. The visions become not a weakness but a well of power, bolstering Tubman’s faith to guide her through danger and darkness.


That unshakable faith is one of the movie’s strongest through lines, and actress Cynthia Erivo inhabits Tubman with fervent authority. Lemmons makes the peril of Tubman’s initial escape and the improbability of her eventual success as a liberator abundantly clear. In a breathless (if somewhat overwrought) sequence when Tubman initially flees, she narrowly escapes capture. Cornered by Gideon Brodess, the son of her recently deceased master, played with sinister insincerity by Joe Alwyn, Tubman declares she will "be free or die."


Against all odds, she manages to live by this creed. This is an action movie, focused on Tubman’s calling as a liberator. Her triumphant quests to free her family and friends are exhilarating. Erivo’s portrayal of Tubman as a woman guided by an unrelenting belief in freedom and God is moving. But with the exception of a few scenes with her husband, John Tubman (played by Zackary Momoh), and her father, Ben Ross (played by Clarke Peters), the movie lacks the kind of strong relationships that reveal a broader depth of character.


Leslie Odom Jr. and Janelle Monáe are regal and gallant as leaders of free black society in Philadelphia, but their limited roles in the movie make the characters feel like plot devices at times. They effectively drive home the point that, for African Americans anywhere in America during slavery years, freedom was always tenuous, but we don’t see enough of their inner lives to fully connect them to the movie’s emotional core.


In the same way, Tubman’s sister, who refuses to flee, demonstrates the complexity of a vicious system that used children as pawns to force their parents into submission.


Still, as an aggrieved plantation mistress played by Jennifer Nettles indignantly laments escaped slaves as a loss of property, and as Tubman deftly dodges mobs of slave-catchers that include profiteering free black men, Lemmons brings to life a dark chapter of our history that is too often whitewashed in modern America.


The heart of the movie is a hero’s journey: Tubman’s evolution from an illiterate slave girl to the most famous conductor on the Underground Railroad. She is a woman who earned her planned place on the $20 bill — a change originally set by the Obama administration for 2020, the status of which is unclear under the Trump administration — with determination, moxie and faith in God. And that is certainly something to celebrate.


Correction: An earlier version of this review misspelled actress Cynthia Erivo’s last name.