See Jessica Chastain as activist painter Catherine Weldon in new 'Woman Walks Ahead' clip

Jessica Chastain's newest role contains a little more artistry than usual.

The Oscar-nominated actress plays real-life artist Catherine Weldon in the period drama Woman Walks Ahead (now available exclusively on DirecTV, in theaters June 29). Based on a true story, the film directed by Susanna White (Parade's End) chronicles the widowed New Yorker's journey to North Dakota in 1889 — alone, mind you — to paint a picture of Native American leader Sitting Bull (Michael Greyeyes). Her arrival and friendship with him embroils Catherine in the Lakota tribe's struggle for their land at Standing Rock against a contingent of Army troops led by Col. Silas Groves (Sam Rockwell).

We've got an exclusive clip from the film featuring Sitting Bull showing Catherine some of his own artwork: "I am a painter, too," he tells her as he tells the story of how he painted Custer's Last Stand after having a vision of it two days before Sitting Bull, Crazy Horse and others took charge of combined Native American forces and annihilated George Custer's men at the Battle of the Little Bighorn. 

"This is one of the most exquisite pieces of work I've ever seen," she says, leading him to ask Catherine why she's sad. Her response: "Because you've lived all this and turned it into something beautiful. The only battle I've ever fought against is insignificance."

But Sitting Bull counters with a great life lesson: "So live more."