Every celebrity story has its ugly chapters, when a star is forced to compromise his self-esteem by appearing in forgettable flops or, worse, attaching himself to the worst dreck the entertainment medium ever vomited.

Getting your name out there is everything, see. That's what makes chasing fame such a thankless business, one requiring an iron stomach and an unflappable willingness to withstand all manner of humiliation.

	Daniel Radcliffe of "Harry Potter" fame plays a horny version of himself while Andy Millman (Ricky Gervais) continues to founder as the star of an embarassing television sitcom.

Andy Millman is perfect for the job, although in this second season of "Extras" (10 p.m. Sundays, HBO) one wonders if the quest for celebrity won't beat him into a sidewalk stain.

Ricky Gervais' HBO comedy, a co-production with BBC, proves that "The Office" was no fluke -- although, thanks to the success of the American remake, his first BBC series has without a doubt received far more attention.

Kind of appropriate, when you think about it; why should a comedy about those nameless faces populating films and television backgrounds be front and center on HBO? The premium channel that has its cool quotient riding on "Entourage," not a chunky guy who stammers his way through uncomfortable conversation.

We don't mean to imply "Extras" isn't cool. The second season has guest appearances by Orlando Bloom, Coldplay's Chris Martin, "Harry Potter's" Daniel Radcliffe and music legend David Bowie, and even without them in the mix, Gervais is about as edgy as TV comedy stars get these days.

Spend 30 minutes with his pudgy, self-deprecating Millman, a middle-age schlub who quit his day job because he was convinced he had "it," and you'll see why. Few stars can write and play a kicked-in-the-mouth underdog as smartly as Gervais does here.

In season two, Millman doesn't just ask for humiliation, he attracts it. Forty-something and desperate for attention, the "background artist" thinks his big break has arrived when his pilot script, "When the Whistle Blows," is made into a series by the BBC.

But in classic TV industry fashion, the network meddles and strains it into a catchphrase-driven pulp. Pandering to the lowest common denominator, "When the Whistle Blows" is rife with crass jokes and spit-takes. Millman's character is forced to wear huge glasses and a wig while cackling "Is 'e 'avin' a laugh?" every 10 seconds. Not even his imbecilic agent, Darren Lamb (series co-writer and co-creator Stephen Merchant), watches it.

In fact, desperate to find a positive review to share with Andy, he reads him a few lines from one on "Wind in the Willows."

Millions of other Brits watch it though, which is most unfortunate for Andy. That may grant him his wish, because he is famous -- famous for being the star of an abysmal sitcom.

This allows "Extras" to explore the various strata of fame and all its perils, because Andy is recognizable, but a star? Not hardly.

Moderate exposure means he and his delightfully dim best friend, Maggie ("Ugly Betty's" Ashley Jensen), gain access to London's best spots, but that only makes it easier for the beautiful people to ridicule Andy to his face. Not even elder statesman David Bowie is above it, and he has enough accolades and style to know better.

Poor Andy makes the mistake of sidling up to Bowie at a posh bar and emotionally unburdening himself to him, thinking a fellow celebrity will understand his pain. Instead, Bowie cuts him off and, as if to remind him he's a peon appealing to an uncaring god, turns to a nearby piano and makes Andy's woes into a catchy ditty about a pathetic little loser who should off himself.

"He sold his soul for a shot at fame/ Catchphrase and wig, and the jokes are lame/ He's got no style, he's got no grace,/ He's banal and facile! He's a fat waste space!"

Gervais established himself as a genius at supremely uncomfortable comedy long ago, but by making his sad sack the butt of the joke in "Extras" -- one lacking the shield of cluelessness David Brent had in "The Office" -- he gives the audience a way of empathizing with him while laughing at him and at his circumstances.

Still, the reason we feel for Andy is because his experiences validate what so many of us think about celebrities, an idea driven home by grocery checkout celebrity rags and tabloid programs: One of the greatest spoils of celebrity is the license to act like a jerk with total impunity.

And "Extras" guest stars play along with gusto. Bloom transforms into an egocentric star obsessed with being a top-ranked hunk in magazine polls -- threatened, naturally, by "Pirates of the Caribbean" co-star and former People magazine Sexiest Man Alive Johnny Depp.

Radcliffe plays himself as a horny adolescent, swinging around an unrolled condom and hitting on Maggie by confiding that he's "done it with a girl, intercourse-wise." This leads to a riotous exchange with Dame Diana Rigg -- the second funniest bit behind Bowie's nightclub act.

Gervais once hinted that these six episodes of "Extras" may mark the end of the series, which isn't unreasonable, since his version of "The Office" only consisted of 14 episodes and a wrap-up special. He has since remarked that he and Merchant had such a terrific time with this second round that he may be up for a third.

Ordinarily, when a series creator is ready to end something, it's for the best to follow that instinct. Nothing ruins great series faster than continuing after the creators lose heart. But with "Extras," Gervais and Merchant continue to maintain a 100 percent success rate. If they can find it in their hearts to go on, they should.

Television needs more comedy like theirs, and desperately. For the sake of elevating the medium, let's elevate "Extras" to the status of necessary viewing.

WATCH IT

"Extras" Sundays, 10 p.m., HBO