On the morning they finished shooting the pilot for “Westworld,” the married showrunners Jonathan Nolan and Lisa Joy commandeered a golf cart and went for a drive around Sweetwater, the Old West town they built for the show on Gene Autry’s former ranch studio in Santa Clarita, Calif.

“The sun filtered through everything, and it was this beautiful moment,” Ms. Joy recalled recently. “For once, there was nowhere to rush, the pages were shot. We rode through that town together, and we were done with this massive endeavor.”

In fact, they were just getting started. Still to come were nine more episodes of this audacious science-fiction western; production delays that would cast doubt on the show’s future; and, as its Sunday, Oct. 2, premiere date was finally announced, the pressure of reviving HBO’s drama slate as “Game of Thrones,” another high-concept epic with lots of violence and naked people, enters its twilight.

Based on the 1973 Michael Crichton film, “Westworld” is about a dark Disneyland where the wealthy can wallow in incredibly lifelike Old West fantasy, shooting or sleeping with whomever they choose. The objects of their depredations are humanoid robot “hosts” who believe themselves to be actual gunslingers, brothel madams and ranchers’ daughters. That is until flickers of memory and insight threaten to reveal that the hosts were actually built by puppet-master scientists, a programmer explains, to “gratify the desires of the people who pay to visit your world.” Myriad awakenings, reckonings and complex existential conflicts ensue.