HOLLYWOOD — Last year, it was known as "the show they canceled 'Deadwood' for." Now, some say it's "the show that could replace 'The Sopranos.' "

Expectations are running so high in some quarters for David Milch's multilayered surf family saga, "John From Cincinnati," launching tonight, its creators don't even want to discuss them.

If HBO, a premiere network in flux, wants to maintain its reputation for high-quality original programming, it must come up with new programs that reach the critical highs of former heavyweights "Six Feet Under" and "Sex and the City" as the popularity of the soon-to-expire "The Sopranos," a cultural touchstone, might be impossible to match.

With the loss of those hits, and the recent forced departure of Chairman and CEO Chris Albrecht, HBO's reputation as TV's incubator of innovation hangs in the balance. So far, newer series "Big Love" and "Entourage" have remained basically niche shows. While HBO has downplayed its expectations for "John," it signaled its ambition by scheduling the premiere immediately after the "Sopranos" finale.

SHARPENED AIM

Unlike broadcast networks, HBO doesn't aim for massappeal blockbusters; each show is "targeted" to specific demographics among subscribers, said Dave Baldwin, executive vice president of program planning. "John," he said, is aimed at men 18 to 34 who are attracted to its themes of surfing and metaphysical mystery.

" 'John' is one we were excited about," said Carolyn Strauss, HBO's president of entertainment.

"John's" promise derives from its pedigree: The 10-part series was created from an idea by Milch ("Hill Street Blues," "NYPD Blue" and "Deadwood"), combined with a pitch from San Clemente surf couple Herb and Dibi Fletcher and input from Kem Nunn, California surf-noir novelist ("Tapping the Source," "Tijuana Straits").

"John" tends to follow a certain HBO formula — an unusual setting, a dysfunctional family, an unconventional narrative and enough creative rope for the executive producers to hang a masterpiece — or themselves. The production has been "crazy as usual" for a Milch project, according to Milch associates. Scripts were written just before shooting began. At least two episodes remained to be shot weeks before the premiere, an unusual situation for HBO.

A MYSTERIOUS GUY

HBO stressed that it did not purchase rights to Nunn's "Tijuana Straits," set in the seamy surfside border city, though "John From Cincinnati" is set in Imperial Beach, not far to the north. Nor, representatives said, does the story about a celebrated but troubled surfing family, the Yosts, have anything to do with the Fletchers' life story, a flamboyant mix of 1960s sunshine and shadow.

In the show, a mysterious, seemingly mentally challenged stranger named John Monad appears and the Yosts' lives start to change in paranormal ways. If you know that a "monad" is the smallest indivisible unit of the universe, and that John delivers lines such as "See God," you get the picture.

During a break on the set, Milch was asked to boil down the premise of the series.

His 20-minute response touched on German philosophy, 9/11 and physics. At some level, he said, the show is about his own sense that all matter "organic and inorganic" is part of a single energy source.

"The idea of the separate identity of each individual is an illusion," he said.

Nunn agreed. "The wonderful thing we hope people would see is the connectedness of these people. In fact, we're all part of the same organism at some level."

As the show unfolds, characters who seem to be separate find out they're having the same dreams. Characters surf waves of time and light along with ocean swells.

John, in other words, isn't really from Cincinnati.