‘The O.C.” used to mean something. It meant cool. It meant funny. It meant introducing the world to new music.

But last year in its third season, “The O.C.” meant only one thing: desperate.

Everyone knew it, including creator and executive producer Josh Schwartz. But a change is afoot when “The O.C.” kicks off its fourth season in the grueling 9 p.m. time slot Thursday on KCPQ, Channel 13.

It will step into the proverbial ring with ABC’s “Grey’s Anatomy” and CBS’s “CSI.” NBC’s sitcoms “Scrubs” and “30 Rock” are also set to move there at the end of November.

But all that means little to the newly “Zen” Schwartz, whose show has lost 4 million viewers since its debut season in 2003, according to Nielsen Media Research.

“Last year, decisions were made that weren’t necessarily creative but that were made sort of defensively, so as to not get canceled,” Schwartz said during a conference call last week. “I think ‘promotable’ events were dictating characters, plus the other way around.

“This year, we’ve gotten very Zen about the fact that we are powerless to control those ratings, and out of that is real creative liberation.

“We’re having a lot of fun, anything goes, and we’re really doing the show that we will be excited to do and our fans will be excited to see.”

While the hope remains that the show will not be canceled, it clearly has an uphill battle ahead. Fox has ordered just 16 episodes for the new season, down from the usual 22. And Schwartz didn’t even flinch, much less get defensive, when it was suggested that the fourth season will likely be the show’s last.

But the new approach is paying off.

The most fun part of the new season comes from Summer (Rachel Bilson) and her “reinvention” as she attends Brown University while leaving Seth back in The O.C. for the semester.

The once-bubbly socialite has gone all green and hippie. The new Summer protests on behalf of caged chickens, old trees in the quad and just about anything that can’t speak for itself.

“I don’t do sarcasm anymore,” she tells Seth. “I’m post-ironic.”

But the first few episodes aim to tie up loose ends from the third season, which culminated in the death of Mischa Barton’s character, Marissa Cooper.

For those who’ve been absent, and a look at the ratings says that’s quite a few of you, Cooper was killed when her last boyfriend, Kevin Volchok, ran her and Ryan off the road. This season, Ryan, the Cohen Family’s adopted son, is out for revenge.

But the battle for Ryan’s soul, as Schwartz calls it, rages early in the new season as the Cohens try to help him out of his grief. Ryan is now working in a bar in a sketchy neighborhood after deferring his admission to UC-Berkeley. Oh, and he’s participating in cage fighting matches where he regularly gets his toosh beaten to a bloody pulp. It’s just his way of coping.

Seth, meanwhile, is helping lead the charge to save Ryan while working at a comic book store in the mall.

It’s nothing but good times on “The O.C.,” regardless of what the ratings say. And that’s good news, because the onetime king of buzz is entering a cage match of its own and the odds don’t look favorable.

Victor Balta’s column runs Mondays and Thursdays on the A&E page. Reach him at 425-339-3455 or vbalta@heraldnet.com.

On TV

“The O.C.,” 9 p.m. Thursday, KCPQ, Channel 13.