Until recently, it had been a few years since the Austin post-rock greats Explosions In The Sky had indulged their gift for making grand, tingly film scores. But earlier this year, the group made the soundtrack for the PBS nature documentary Big Bend: The Wild Frontier Of Texas. Next month, they’ll release their soundtrack album for the doc, and we’ve already heard the early singles “Climbing Bear” and “Flying.” Today, EITS have also shared “Nightfall,” a short and atmospheric instrumental built on eerie little bell sounds and massive drum thuds. Below, listen to “Nightfall,” which comes paired with a slow-motion video of a bat in flight.

Big Bend (An Original Soundtrack For Public Television) is out 10/1 on Temporary Residence. You can watch the Big Bend documentary here.