LOS ANGELES – The shorthand theme for the fall television season: “To be continued … maybe.”

Inspired by the creativity – or the ratings – of “Lost,” “Desperate Housewives” and other shows with open-ended episodes that carry viewers from one week to the next, the broadcast networks have become serial junkies.

Brace yourself for dramas with intricate, ongoing plots about kidnappings, novice superheroes and fugitives from justice, all easier than ever to follow with TiVos, Web casts and iPods banishing any excuse for missing episodes.

And therein lies the problem.

Just when you’re truly hooked by the dangling story lines and emotional dilemmas, odds are that many of the shows will be canceled. You’re unlikely to learn the ending, happy or otherwise, because you didn’t have enough company in the Nielsen ratings.

“There’s been a lot of backlash about shows that viewers get invested in and then they end before the ending, like (last season’s) ‘Threshold’ or ‘Reunion,'” said analyst Shari Anne Brill of ad-buying firm Carat USA. “I’m still annoyed that I never knew who the hell ‘John Doe’ was.”

Brill’s chagrin over the truncated 2002-03 Fox series about a mystery man with encyclopedic knowledge (starring Dominic Purcell, now on the run in Fox’s “Prison Break”) shows how long viewers can hold a grudge.

Given that this is one of the best-reviewed seasons in years, the heartache could really endure.

The cruel reality is that nearly one-third of new fall series will be off the air by January, according to Brill’s calculations. That’s not unusual: Of the 57 major broadcast network series that debuted last season, only 26 percent are back this year.

But the success of Fox’s “24,” which follows a day’s events over the season, and ABC’s “Lost,” which is weaving an elaborate story over not just episodes but years, led to TV’s typical follow-the-leader mind-set even at the risk of alienating fans of failed serials.

“Whenever we have a style or approach that’s successful” it gets copied, said analyst Bill Carroll of ad-buyer Katz Television. “We’ve gone from the age of the procedural to the age of the continuing drama.”

Crime dramas “Law & Order” and “CSI” and their spin-offs, which wrap conflicts up neatly within each episode, remain popular. But it’s complex, twisting plots and layered characters that have the momentum.

So among the season’s 12 new dramas are Fox’s “Vanished,” with a senator’s wife gone missing; NBC’s “Kidnapped,” about the abduction of a rich kid; new network CW’s “Runaway,” with a family on the run after the dad is accused of murder; ABC’s “The Nine,” which follows the aftermath of a hostage crisis, and NBC’s “Heroes,” about regular Joes and Jills given superpowers.

There are newcomers of a different stripe with considerable buzz, including NBC’s “Studio 60 on the Sunset Strip,” which marks the return to TV of “The West Wing” mastermind Aaron Sorkin, and ABC’s telenovela-flavored “Ugly Betty.”

If this is a new golden age of drama, as critics and industry insiders consider it, that’s borne out at least numerically: In all, there are 50 new and returning dramas this fall on ABC, NBC, CBS, Fox and CW (the product of the merged UPN and WB).

By contrast, the introduction of nine new comedies will bring the total number to just 23, far less than the 42 sitcoms last season.

The hour-long comedy “Ugly Betty,” based on Colombian telenovela “Yo Soy Betty La Fea” and starring America Ferrera (“Real Women Have Curves”) as an unchic young woman in the fashion world, has earned praise.

Telenovelas, limited-run soap operas, have been highly successful in the United States on Spanish-language networks such as Univision and Telemundo.

While “Ugly Betty” has designs on more than one season, programs that hew closer to the traditional telenovela format are the mainstay of debuting MyNetworkTV, the Fox-owned answer for those WB and UPN affiliates left out when CW formed.

“Desire” and “Fashion House” are airing each weekday on MyNetwork, to be replaced after 13 weeks by other novelas. The question is whether English-language American viewers will take to the genre.

The other newcomer, CW, also faces hurdles – as do its viewers. Although returning shows like WB’s “Gilmore Girls” make up much of the CW schedule, the shows may require some detective work to find.

For instance, in nearly 70 percent of TV markets UPN viewers must switch to a different station to watch CW. WB audiences have less of a burden, with nearly three-quarters of former WB stations becoming CW affiliates.

– The Associated Press