Westworld type TV Show network HBO

HBO showed an extended trailer of its mysterious sci-fi Western drama Westworld at the ATX Television Festival on Saturday and the audience was hugely impressed.

The trailer, which was set to The Rolling Stones’ classic “Paint It Black,” included intense Western action along with horrifyingly creepy sci-fi moments. The premise turns Michael Crichton’s original 1973 film version of Westworld on its head — instead of human theme park patrons being terrorized by ultra-realistic humanoid robots run amuck, the series has its the artificially intelligent robots taking center stage as they’re used and abused humanity’s darkest impulses.

“Our show is about the robots who don’t realize they’re in a fake Western,” says showrunner Jonathan Nolan, who was on a panel with his fellow showrunner on the series, Lisa Joy.

Much of the trailer focused on Evan Rachel Wood, a woman in the Old West who gradually realizes her reality is false. Anthony Hopkins plays Dr. Robert Ford, the creative director of Westworld, and one haunting exchange between the two had Wood’s character innocently asking if they were friends, and Hopkins explaining that’s not what they are at all. Another shot had androids trapped in a torturous chamber.

After the trailer screened, Justified showrunner Graham Yost commented, “There’s a part of me that ached with envy [watching the trailer]. But I cannot wait to see that show.”

Jonathan Nolan credited HBO’s lavishly produced Game of Thrones for pulling off the show, which was delayed for months before being scheduled for this fall.

“It was actually Game of Thrones that made us feel like we could pull this off,” Nolan said. “We actually pitched this as making Days of Heaven and Alien simultaneously and then cutting them together. Game of Thrones was the inspiration for this. Thrones had this commitment to practical production value, which is not necessarily whats in vogue these days … [Westworld] had to have this big scope.”

Westworld was first announced two years ago and was beset by recasting and production delays which have caused some in the industry to wonder about the show’s prospects. But the last HBO drama to have such a tortured development process eventually became the network’s biggest hit — Game of Thrones.

Here’s some more reactions to the trailer:

And here’s HBO’s previously released short teaser for Westworld. (Note: This is not the footage that screened at ATX, which is not yet available online.)

Last month, HBO confirmed Westworld would debut in the fall with a 10-episode first season.

Entertainment Weekly is on the scene at ATX in Austin, Texas. Go inside the TV festival with all our coverage, available here.