LOS ANGELES – When the most important show on NBC’s prime-time schedule, “Heroes,” returns to the air on Sept. 22, it will have been out of sight for nine months. Its creator, Tim Kring, can only hope that it has not been out of mind for some of the most passionate fans in television.

“A little absence can really be a benefit,” Kring said, citing other “event-like shows,” such as “The Sopranos,” that have rebounded from long gaps between seasons. In the intervening months, he said, viewers “have seen a lot of stuff on TV that wasn’t of the quality of ‘Heroes.’ I think they’ll be raring to go.”

NBC executives certainly hope so. “Heroes” is the network’s biggest hit, and as Ben Silverman, the co-chairman of NBC Entertainment, noted, “it’s a global franchise,” selling to a long list of international networks.

But for a still-new hit series, “Heroes” has had a somewhat rocky ride, fueled by a truncated season last year and by the reactions of those rabid viewers.

“The double-edged sword of our fan base is they have a passion for the show,” Kring said. “And that passion cuts both ways. It cuts towards, ‘You’re the greatest thing ever’ and towards ‘You’ve disappointed me.’”

The scale tipped toward disappointment at the start of last season, as Kring acknowledged in an interview way back in November, just after production was abruptly cut off by the writers’ strike that shut down Hollywood. At that time, he cited a list of early missteps, including introducing too many new characters, dabbling too much in romance and depositing one of the fans’ favorite characters, Hiro, in feudal Japan for too long.

In an interview over lunch, accompanied by Katherine Pope, who heads the NBC Universal studio that produces the series, Kring was enthusiastic about the new season, or “volume,” as he calls it. (“Heroes” has used the language of the comic book from the beginning.)

The new volume, which will run in 13 episodes, is called “Villains” and will focus on a single story line, Kring said, relying on its core of main characters, and will return the show to exploring what he called “the primal questions” from season one: “Who am I? What is my purpose?”

The audience got used to the “adrenaline pace” from the end of season one, Kring said, and when season two started with the introduction of still more new characters, the viewers “lost a bit of patience for the buildup.” That has led him to conclude that “when any new characters come in, we need to connect them to the story line and characters they’re already familiar with.”

The long dry spell for original episodes will be less a problem, Kring said, because of a decision he made at the 11th hour in December. The original idea for the second volume of last season was for a vial of some deadly plague to be released in the finale of “Generations,” setting up eight episodes of the next volume, “Outbreak.”

Instead, sensing that a long strike was looming, Kring had an inspiration. He decided to reshoot the ending of “Generations,” having the Peter Petrelli character (played by Milo Ventimiglia) catch the vial filled with deadly virus just before it was to hit the ground and explode, thus ending that story line and conveniently wiping out the entire next eight-episode story arc.

“That turned out to be a very, very smart decision,” Kring said. With the germ-outbreak story line gone, it was assumed that “Heroes” would not come back, as many series did, for an abbreviated run last spring after the strike ended. Instead, the show’s creative team began to plan for the coming season, which, thanks to the extra time, will now be extra-long (25 episodes instead of 22), broken into two sections.

The new season will begin with two episodes back to back from 9 to 11 p.m. Sept. 22, following an hourlong special with stars doing interviews about their characters.