Is '24' running out of time?

JACK BAUER, America's favorite counter-terrorism agent with the violent code of honor and the weird sadomasochistic bent, is squaring off against a stealthy and unforgiving new enemy.

His fans.

After peaking in the ratings last year, Fox's thriller "24" has been getting dumped on by seemingly everyone in this, its sixth season. Critics and fans alike are aiming tomatoes at the stage, carping about the soapy and repetitive plotlines that unspool Jack's unlikely familial past, tiresome romantic triangles in the security bureaucracy and endless bickering among Oval Office advisors.

Last week, with a fresh episode designed to lay the groundwork for what the creators promise will be a typically suspenseful finale next month, "24's" ratings in the key young-adult category swooned to their lowest level in more than three years, with a total audience of just 10.4 million, according to figures from Nielsen Media Research.

More than one-third of viewers have bailed since the special four-hour season premiere that aired over two consecutive nights back in January. And if that wasn't enough bad news for the series, last week "24" was one of the prime-time shows that the Federal Communications Commission singled out in urging Congress to curb TV violence.

The vox populi protests have not escaped the attention of the show's producers, who promise that some big changes are on the way for Jack (Kiefer Sutherland) and other regulars next season. There's also speculation that something else might be at work in accounting for viewers' tune-out this season, but more about that in a minute.

"It hurts to hear the criticism," said executive producer and writer Howard Gordon, who spoke with me last week by phone as the cast and crew crashed to finish shooting the season's final episode, set to air May 21.

"I don't dispute it's been a challenging season to write for us. But it's reinvigorated our determination to reinvent the show. This year could be seen to be the last iteration of it in its current state."

Oh, dear. Reinvention? That does sound ominous. But Gordon says not to worry, as Jack "won't be flipping burgers."

"It won't be a musical or a half-hour," he added. "I've got a couple ideas, none of which I could even begin to share responsibly."

So "24" — the TV institution, to say nothing of the show's ongoing narrative — has at last arrived at a crossroads, and what an odd trip it's been.

Premiering less than two months after the terrorist attacks of 9/11, "24" initially amounted to barely a blip on the pop-culture radar. The premise — each episode unfolding in real time over the course of a single day as Jack races to foil some dastardly conspiracy — sounded gimmicky. And given recent American history, Jack's missions against Middle Eastern bad guys could easily have struck too close to home. (As it is, the show has prompted plenty of complaints for propagating noxious ethnic and religious stereotypes; witness this season's major plot involving a diabolical terrorist overlord named Abu Fayed.)

But Fox stuck by the show, and, thanks in large part to the about-to-explode television DVD market, it steadily grew a fan base that finally made it blossom into true hit-level status sometime during the critically acclaimed and Emmy-winning fifth season.

I always loved "24's" willingness to work without a net, to go to crazy extremes in expanding the thriller format and somehow live to tell the tale — to outLudlum Robert Ludlum, as it were.

But two personal anecdotes brought the show's mass appeal home for me: My 70-something mother-in-law, a rock-ribbed Republican with narrow TV tastes outside of "The O'Reilly Factor," confessed that she never missed "24." And last year, while walking in downtown Burbank, I happened to observe a middle-age man take his female companion's hand and inquire, in a tone of voice at once soothing and conspiratorial, "What do you say we go home, build a fire and watch '24'?"

But the clock is ticking, for fans as well as for Jack Bauer. Longtime devotees are struggling to keep the faith during this trying season.

"The writers have recycled some plots this season that are glaringly obvious: a recording, an almost removed president, an assassination attempt on that president, an attack on a Middle Eastern country, an impending nuclear strike, a person close to Jack kidnapped, etc.," Victor Lana, a novelist who follows "24" for BlogCritics Magazine, wrote in an e-mail. But "the bottom line is that we still care about Jack Bauer."

Meanwhile, with apologies to my mother-in-law, "24's" audience is getting noticeably grayer, typically a sign that a show is losing its purchase on the windy crags of pop culture. According to Brad Adgate, senior vice president at the New York ad firm Horizon Media, the median age is 47.4 so far this season, compared with 45.1 last year and 42 in the 2003-04 season.

Those born with resistance to "24's" charms have noted that in the second and third seasons the show benefited from following "American Idol." Now, though, its scheduling is cutting the other way: In recent weeks the show's Monday lead-in was "Drive," a new cross-country caper that bombed and got yanked last week. (The network hastily replaced it with reruns of "House.")

"We had every hope that 'Drive' would be a good companion to '24' and successor to 'Prison Break.' We were wrong," Fox Entertainment President Peter Liguori told me, adding quickly that he nevertheless believed "24" would bounce back stronger next year.

But Gordon said he and his writing staff were wondering if something else was afoot besides the normal cycles of storytelling and network scheduling.

Could it be that the vague but gnawing post-9/11 fears that helped turn "24" into a hit are ebbing — the nightmares that envisioned great cities laid low by chemical weapons spilled into the water supply, say, or suitcase nukes wielded by shadowy assailants?

"It's something we talked about at the beginning of the season," Gordon said. "9/11 is becoming, quietly, a memory; the memory is starting to fade…. I do think that people are looking at the world differently, with less fear."

If so, that's probably good for America. And alas, that's probably bad for "24." Real-life political tension does wonders for creators of thriller fare. Look how kind the Cold War was to Ludlum and Tom Clancy.

Even so, Gordon sounds optimistic that "24" can recover from its annus horribilis and deliver the goods next season, no matter what changes are ultimately in store for the ever-suffering Jack Bauer.

"Certain tropes of the show will remain the same," Gordon said. "It'll keep its contract with the audience. We'll keep the adrenaline going."