“Extras,” Ricky Gervais’s follow-up to the hit British series “The Office,” is back for its second season on HBO. “The Office” was a rarity among foreign comedy shows in that it spawned a successful American counterpart. Not having been adapted for American audiences, at least as yet, the uncompromising Englishness of “Extras” has so far been a sticking point. It’s a bit like “Entourage” injected with a megadose of Valium, or “Curb Your Enthusiasm” afflicted by a slow-acting suicide pill. There is little comic catharsis, and the laughs tend to be small and located in a particularly dyspeptic portion of the belly.

The show, which is written by Mr. Gervais and his “Office” writing partner, Stephen Merchant, is about small-time actors in the worlds of film, theater, and television, each a distinct circle of hell. Failure and the lure of fame are the themes. Ambition is exacerbated by the occasional droplet of success, which almost immediately disappears without trace.

Mr. Gervais plays Andy Millman, a struggling actor whose humiliating career as an extra was documented in the show’s first season. Now fame beckons: A sitcom he wrote and stars in has been picked up by the BBC. Called “When the Whistle Blows,” it’s a hideously old-fashioned working-class version of “The Office” — a sitcom for morons, shorn of any postmodern irony or postmodern anything. It’s the kind of thing Mr. Gervais might actually have written if he didn’t have any talent, though one can’t imagine the BBC putting it on.

Despite receiving some of the most vicious reviews ever, Millman’s pilot (which he knows is terrible) attracts 6.2 million viewers. In next week’s episode, he is recognized and drooled over at his local pub by feverish, semi-demented celebrity-addicts whose behavior understandably repulses him. So together with his agent, Darren Lamb (Mr. Merchant) and his only friend, Maggie Jacobs (Ashley Jensen, playing a fellow extra of bovine stupidity), he repairs to a high-class showbiz hangout where there will be no rabble to hound him.

Big mistake: Suddenly Millman is thrust into a world of real celebrities. When he makes the further mistake of pouring his heart out to David Bowie, who just happens to be seated next to a piano in the VIP section, the rock star replies by improvising a song about just how ugly, awful, contemptible, and unfunny Millman really is: “He sold his soul for a shot at fame / catchphrase and wig and the jokes are lame.” Soon the entire nightclub is merrily singing along, including his agent and friend, while Millman sits there and takes it. Yes, he’s famous. (David Bowie is singing about him!) And he’s despised.

The Bowie song aside, much of “Extras” drifts along like rock ‘n’ roll with only a faintly detectable beat. It’s in love with gaffes that cause painful, protracted silences — the notorious British propensity for embarrassment — in a way that is somewhat anachronistic. (Embarrassment may not be dead in England, but it’s not exactly thriving.) Like “The Office,” “Extras” portrays a certain milieu with drab, documentary realism, but then has its characters behave in ways that often defy belief. It divides the world into winners and losers, with the former being unbearable and the latter tedious or stupid. But while the misanthropy on a program such as “Curb Your Enthusiasm” is invigorating, here it’s dispiriting, like flat champagne.

Messrs. Gervais and Merchant are sufficiently aware of the problem to liven things up with regular star appearances from the likes of Orlando Bloom, Patrick Stewart, Daniel Radcliffe (aka Harry Potter), Dame Diana Rigg, and Mr. Bowie, among others. Often the stars gamely make fun of themselves and their own vanity, though of course we are aware that they are mocking themselves in patently absurd ways rather than ones that might be plausible.

In other words, nothing to worry their fan base. Last season, there was an episode in which Mr. Stewart talked about a nonsensically egotistical film script he was writing in which he would be endowed with magical powers, allowing him to divest women of their clothes in virtually every scene. In this season’s opening episode, Mr. Bloom portrayed himself as being unhealthily obsessed with his own good looks. Mr. Bowie, not sending himself up at all, lets loose with pure musical venom. And in a later episode, Ms. Rigg consents to having an unrolled condom land on her head while she’s eating lunch, alone. Somehow I don’t think this will rank as one of the high points of her career.

As in “Curb Your Enthusiasm,” or in the work of Sacha Baron Cohen, much of the comedy centers around politically incorrect subjects — dwarves, children with Down syndrome, flamboyantly over-the-top homosexuals. But Mr. Gervais rarely makes you howl with laughter the way Larry David or Mr. Cohen can. The funniest bits tend to belong to his devious, incompetent agent, who appears not to have heard of a single actor, television show, or movie ever made.

Just as “The Office” was enough to put anyone off working in the paper industry, “Extras” is one long poison-pen letter to the siren song of celebrity and fame. If ever there was a program to make young people starting out in life consider a career in law, medicine, waste disposal, or just about anything other than drama, this is the one. At least that way you won’t end up on television like Ms. Rigg, with a prophylactic on top of your 68-year-old head.

bbernhard@nysun.com