One Austin film icon passes the torch to another for a deep dive on Texas' river ecosystems in the upcoming documentary Deep in the Heart 2: Texas Rivers. Matthew McConaughey narrated the original 2022 film, Deep in the Heart: A Texas Wildlife Story. Now Ethan Hawke narrates the follow-up, which will be in theaters September 25.

Deep in the Heart 2 is directed by Ben Masters, a nature-obsessed Texan who was born and raised in Amarillo and has followed wildlife around the state and beyond. Working with his crew at Fin & Fur Films, Masters explores the Rio Grande, the Sabine River, and the Neches River, a press release says, coming across otters, turkeys, alligator snapping turtles, and more.

This underwater shot was taken in San Marcos.Still from Deep in the Heart 2: Texas Rivers

The original Deep in the Heart took a broad view of Texas — both its landscapes and their inhabitants — while the "sequel," as the release calls it, specifically highlights water. Conservation is an important angle, and viewers will get a chance to consider how they could connect with and protect the ecosystems on their screens.

"Most of my favorite memories are on Texas Rivers," said Masters in the release. "I grew up on the Canadian, fell in love on the Brazos, got married on the Guadalupe, found adventure on the Rio Grande, and am raising my kids on the Colorado."

The filmmaker says that spending three years filming his natural subjects gave him "a newfound appreciation" for rivers and how distinct they are from one another.

Amazing cinematography was a hallmark of the original film, and the sequel offers more beautiful shots.Still from Deep in the Heart 2: Texas Rivers

"We spent months filming mountain lions on the Pecos, snapping turtles on the Neches, otters on the Sabine, fatmuckets on the Llano, and whooping cranes in the Guadalupe's Estuary," Masters said. "Editing the majesty of Texas Rivers into 80 minutes was a huge challenge, and I'm just incredibly grateful to work with such a talented team of cinematographers, editors, producers, and musicians."

Hawke, born an Austinite and raised in Fort Worth, is known for acting in the Dead Poets Society, Gattaca, the Richard Linklater films Boyhood and Blue Moon, and more. He has taken up causes in environmental advocacy for years and appeared in other ecology-focused films, including the intense fictional First Reformed (2018) and a goofy anti-littering PSA with TxDOT (2023).

Some unexpected guests in the Rio Grande.Still from Deep in the Heart 2: Texas Rivers

The film was made in association with H-E-B, a regular supporter of ecological documentaries and initiatives, and conservation organization Texan by Nature. Other collaborators include producer Josh Winkler, editor Sam Klatt, assistant editor Chet Stefan, and composer Noah Sorota. The musical score is performed by Dallas Chamber Symphony.