Though Nora Ephron's “Bewitched” meets its expected quotas of spells, hexes and flying brooms, little if anything about the movie feels magical. Ephron (“Sleepless in Seattle”) has merely taken a corny, lovable television show and retooled it as a corny, cripplingly ironic tale of celebrity romance. Talk about dark arts.

With her pitch-perfect nose-wiggle and adorable air of Valium-bottle befuddlement, Nicole Kidman (“The Interpreter”) lends “Bewitched” what little charm it has. She plays Isabel Bigelow, a modern-day witch who — like Samantha Stephens in the TV show — craves the mundane trappings of a nonmagical marriage. Scolded by her father (Michael Caine) for abandoning her heritage, Isabel has forsworn her powers, aside from the occasional swipe of a tarot card, which she uses like a balance-free Visa.

To make her dreams of marital security come true, Isabel wants to find the most insecure, unstable man possible, someone who makes her feel “thwarted” (this is either the most contrived or most ingeniously satirical romantic fetish ever invented — I'm not sure which). As if by magic, she finds him in Jack Wyatt (Will Ferrell), a fading Hollywood leading man who — pay attention, now — happens to be playing Darren in a modern-day sitcom revival of “Bewitched.” And Jack, ignorant of her witchy nature, wants Isabel to be his Samantha on the show.

So what we have now, clinically speaking, is a show-within-a-show-within-a-movie, a rare cinematic mutation that never fails to yield perfectly inauspicious results. It gets no better when Isabel finally pegs Jack for a self-centered ninny and sabotages his work on the show, prompting Ferrell to unleash his singular brand of hit-or-miss foolwork, which has slouched largely toward “miss” of late (see “Kicking & Screaming”).

Later, a chastened Jack finds himself drawn to the newly assertive Isabel, leading to the single most anemic, unsexy, unromantic “gettin’ to know you” montage this side of a Valtrex commercial. As we watch Kidman and Ferrell blandly cavort on a TV soundstage, it becomes depressingly obvious that Ephron (who wrote the script with her sister, Delia) finds these characters just as uninspiring as we do.

Like Ephron's previous directing effort, the John Travolta/Lisa Kudrow caper-romance “Lucky Numbers,” “Bewitched” is under-miked, under-lit and under-acted (Shirley MacLaine is a nonentity as the actress who plays Endora). Nor does it feel particularly timely. Like another Kidman-headlined revival project, “The Stepford Wives” (2004), this is a story that sexual politics has made somewhat obsolete. In the original TV series (1964-72), Samantha's supernatural advantage over her husband was symbolic of changing times. What could it possibly symbolize now? A lack of producable scripts, maybe.

Obviously, the Sisters Ephron wanted “Bewitched” to be distinct from the current spew of remakes, but disguising it behind a reflexive, postmodern gimmick hardly absolves it of being a “crass attempt to capitalize on nostalgia,” as one character pegs the show. If anything, the Ephrons get so lost in their own cleverness, they lose their certainty. We divine as much from the closing scene, when their wispy illusion of romance literally vanishes before our eyes.