The real thrill, though, is that the series isn't content to be way- cool clever. Instead, it's empathetic, putting its own preposterousness to emotionally expressive use. Keep your parties of five and your so-called lives to yourselves; I can't think of a TV show that better captures how adolescence feels - and in ways that aren't true of adulthood, or anyhow shouldn't be, how adolescence feels is what adolescence is. Granted, the first time I tuned in, I was hoping for camp silliness, and couldn't see for the life of me why the series seemed to be taking all this foofaraw so seriously. But camp silliness we all already know, and for a show called "Buffy the Vampire Slayer" to treat its foofaraw in earnest, or at any rate let its characters do so, is a terrific stroke - not to mention an act of wondrous compassion toward the youth audience. If there's a distinctive new note in '90s TV and movies, it's the discovery that earnestness in explicitly silly contexts can have the same kind of impact that irony in implicitly serious ones once did, and for the same reason: it gets at something true.

      What that might be was certainly no concern of the amiable but purposeless 1992 movie from which this series derives. Even as entertainment, the big- screen "Buffy" ran out of inventiveness fast. But Josh Whedon, who wrote the movie's screenplay, must have figured out that he'd latched on to an idea potentially deeper than farce when he invented a typical teen who glumly learns that it's her destiny to fight vampires in between homework assignments. As creator-cum-exec producer of the TV version, he's turned the story into the fable it deserves to be.

      To be singled out for some inscrutable purpose that estranges them from their peers probably describes the sensations - and so what if it's not the literal experience? - of half the teens alive. Buffy's main advantage over her puzzled real-life counterparts is that at least she's been instructed on her mission - by Giles, the "Watcher" deputized to train and mentor her, whose day job is running SunnyDale High's surreally gloomy if believably empty library. Yet while high schoolers of both sexes can presumably identify, the nifty resonances the show gets out of its premise would be drastically reduced it its title were "Biff the Vampire Slayer"; you bet we're talking a female-empowerment saga, and so far as telling kids home truths goes, the show's clear-eyed recognition that autonomy can be one hard row to hoe (Buffy's reluctance to take up her calling seems sensible to me) puts it miles ahead of upbeat ads about girl Little Leaguers.

      Whedon's been lucky in his casting here, which wasn't true of the movie. There, the Watcher was a sheepish-looking Donald Sutherland, giving a great performance as a guy who hoped Kiefer wouldn't buy a ticket; the Giles of the TV version, Anthony Stewart Head, has the right scrupulously measured combination of weary wisdom and attentive concern. (Unlike Sutherland, Head's not one to hedge the conviction he brings to a role; he's been playing the male half of the Taster's Choice couple for years - and darned well too, don't you think?) Sarah Michelle Gellar's improvement on the movie Buffy starts with the physical contrast, since Kristy Swanson was one of those vigorous California blondes who look perfectly capable of decking most men with one punch. Her TV successor is petite and prepossessing, which gives an exhilarating extra charge to Buffy's whirligigs of martial-arts derring-do.

      Gellar's mingled determination and regret - Buffy turns pensive whenever she pauses - is also very affecting. Her expressions keep reminding you that being a vampire slayer is a pretty lonely life - you know, just like the ones lots of normal teenagers have, only Buffy can't see it that way. Another nice touch is the way she and the two friends she's entrusted with her secret - reliable, good-hearted Xander (Nicholas Brendon) and brainy Willow (Alyson Hannigan) - double as the school's smart-kid misfits, whose chumminess with Giles annoys students and faculty alike. (teacher's pets they're not; by high school, the smart kids have pet teachers - a nuance the series captures very well.) Being a child of divorce with an MIA father also adds a dimension to Buffy's connection with Giles that no doubt works as wish fulfillment for teen viewers whose home lives fit the profile, but the show's real shrewdness is in how the freakish context stops these undercurrents from cloying. Instead, the premise puts fresh spins on teendom's every banality. For instance, Buffy's mother is a pleasant woman who can't understand why her daughter's so moody and withdrawn. But we do: she's got to go out and slay vampires, and her mom doesn't even know they exist.

      Although Buffy herself has no special powers - she's just staunch - the show's supernatural frame gives it room to delve into the stuff that's routinized on its mundane counterparts at often startling levels of satiric cunning and spooky beauty. You can't help but be aware of how the series affects to ignore teen sexuality (Buffy's calling sure louses up her dating life) while sublimating its terrors; the monsters our heroine faces are plenty creepy looking, but most of the time they're also identifiably male - and certainly adult. Still, not all the threats are outside. In one of the best recent episodes, everyone's bad dreams came true in real life, with results ranging from corny (Xander showing up for school in his underwear) to unsettlingly suggestive (our heroine becoming a vampire herself) to, I swear, poignant: gazing down at a tombstone with Buffy's name on it, Xander wondered aloud whose nightmare this was, and reserved Giles muttered, "Mine."

      The show's elaborate visuals live up to the premise's ingenuity. There's always something going on - like the school's walls showing up unexpectedly shrouded in plastic, as if Christo had just signed on as janitor. Clearly, Rod Serling was hired long ago as guidance counselor; last week, the school's socialite contingent, including Buffy's foil Cordelia (Charisma Carpenter), got stalked by a vengeful, unseen marauder, finally identified as a classmate so often overlooked that she'd literally turned invisible. (At one point, a briefly chastened Cordelia confessed that being popular didn't make her feel any less alone, leading an incredulous Buffy to wonder why she still worked so hard at it. "It's better than being alone all by yourself," Cordelia answered - tartly, not plaintively.) In the coda, the stalker, spirited away by X-Files-ish government agents, wound up in a classroom filled with her fellow invisibles from other schools - all of them opening FBI manuals at their apparently empty desks to study their new careers as assassins. It was splendidly scary; sad, too.

      No doubt, a lot of the show's appeal depend on how you remember high school. Me, I never went wild over "Room 222". But I watch Buffy and her cohorts holding their feverish confabs before they charge off to do battle in the night, and chortle with delight at the verisimilitude; damn, that's exactly how it was. I also think the show's title, which looked pretty dopey on theater marquees, is pure television poetry - even if I instantly turn geezer every time, to my dismay, I catch myself humming it to the tune of an ancient Warren Zevon song.