FOR a guy whose once-invincible series is showing signs of creative limbo and ratings droop, Tim Kring doesn't sound worried.

"Heroes," Kring's comics-like confection that became a sleeper smash for NBC last year, looks mired in the proverbial sophomore slump. And it's as good a symbol as any of the networks' generally dashed expectations for what's shaping up as a crummy fall TV season.

In the case of "Heroes," critics are complaining about slow pacing and an overabundance of characters. As if last season's dozen-strong ensemble of ordinary superheroes and shadowy figures didn't offer enough competition for viewers' attention, the producers have added four new cast members, including Kristen Bell (late of "Veronica Mars").

And Masi Oka's character, Hiro, who broke through last season, has been trapped in a goofy, feudal-Japanese subplot that resembles a parody of "The Last Samurai."

In perhaps the most democratic sign of unrest, People magazine, which doesn't typically go harsh on pop-culture phenomena, recently ran a sidebar with prescriptions on how to fix "Heroes."

THE ratings seem to reflect viewer dissatisfaction. Last week the series sank to its lowest numbers yet in the key adults, ages 18-49 demographic, according to early data from Nielsen Media Research, possibly erasing the show from the Top 10 for the first time (final results for last week won't be available until Tuesday).

Yet none of this seems to perturb Kring, who sounds persuasively upbeat about the show's prospects. He says much of the nattering is to be expected, given last year's enormous success.

"People tend to look at last season and see things in it that were not in it," Kring told me by phone. "We haven't deviated that much" from last year's formula.

He did concede, however, that because he and the other writers already know where all these story arcs are headed, it's difficult to plug into the average person's viewpoint: "It's hard to gauge how it's experienced, especially when we're 10 episodes ahead of the audience."

And as for the ratings? Kring points to the now-familiar litany of alternative means of viewing, like TiVo, DVDs and online episodes, that allow people to watch a show other than when it's scheduled.

To be fair, "Heroes" is hardly the only returning series that's run into network TV's punishing new math. Last week, "Ugly Betty" slid to some of its lowest numbers ever, as did "Grey's Anatomy." The new shows aren't burning up the charts either, with many heavily publicized entries such as NBC's "Bionic Woman," ABC's "Big Shots" and CBS' "Cane" posting alarming declines.

Ratings for live viewing of prime-time shows are down at all five English-language broadcast networks, dipping an average of 11% among total viewers compared with last year. Cable networks are hanging tough with zero growth, which counts as a major victory in the current environment.

"I have been a little disappointed by the early ratings," said Andy Donchin of New York ad firm Carat. He added: "It's still very early in the season. Shows can start off slow and come back."

But this may be more than just early-season blahs. There's an unsettling sense of epic industrial shift afflicting the media business, as the old way of doing things curls into the mist of history, replaced with ... what exactly? No one knows. It's making everyone crazy.

And in the midst of this paradigm-shifting angst, Hollywood is in an uproar over a possible writers' strike that could come as soon as Thursday. While few observers expect a work stoppage quite that early, labor unrest is adding a dark cloud to an already-gloomy TV industry.

The ground shook a bit this month when CBS chief Leslie Moonves, usually a tireless cheerleader for TV, glumly told the New York Times, "I'm a bit concerned about the state of network television generally."

As readers of this column know, Nielsen has shaken up ratings this season by roughly doubling the size of its sample devoted to homes with DVRs. And it's true that after delayed viewing is taken into account, the ratings picture looks much brighter. When ratings include those who watch a saved show within a week of its original airing ("live + 7," in Nielsen jargon), the five networks collectively are down just 4% in total viewers and off by a statistically insignificant 2% in adults ages 18-49, according to Magna Global, a large media buying firm.

Advertisers have agreed to pay only for viewers who watch programs within 75 hours of their original airing. But experts still consider the "live + 7" data important because it reveals a show's popularity.

The audience for NBC's "The Office" may not look impressive during the live airing, for example, but for the first two weeks of the season, 2.5-million viewers watched the program within a week on DVRs, representing nearly one-quarter of its overall audience.

Overall, Fox and NBC register small year-to-year declines in terms of live viewing, but each leaps to a robust 11% gain among young adults when "+ 7" viewing is factored in (ABC is flat and CBS and its sister network The CW are down).

FOX'S medical drama "House" has bucked overall trends with strong numbers even in live airings. And Fox scheduling guru Preston Beckman points to some new shows -- including ABC's "Dirty Sexy Money," CBS' "The Big Bang Theory" and NBC's "Life" -- as under-the-radar players that may go the distance.

"These aren't the shows people are jumping up and down about, going, 'These are the next big thing,' " Beckman told me. But "networks have to figure out what the new math is, what separates the hits from the misses."

Even with lowered ratings, "Heroes" is firmly in the "hit" category. And that may explain why Kring feels confident as the show strides toward midseason.

Unlike last season, in which all 23 episodes built to an end-of-the-season climax, the producers this year split up the storytelling, with the first "volume" due to be wrapped in the 11th episode. Plot strands that viewers have found tantalizing or just frustrating -- what was the deal with Hiro's murdered father (George Takei) anyway? -- will be explained, Kring promises. "It will all be paid off by episode 11," Kring said. "From seven to 11 are the best episodes we've ever done."

"Heroes" is an important show, last season's biggest hit. So if Kring's right, then a couple of months from now everyone may forget all about the gripes and falling ratings. And if he's not? A season that started slow may take an awfully long time to end. And not just for "Heroes." That's assuming, of course, that the strike doesn't kill what's left of the season.