While these drawbacks might upset a more ambitious writer, as far as Mavis is concerned she's totally winning, in the Charlie Sheen sense of the word. Brought up with an inflated sense of self-importance that's been aided and abetted by her parents, school pals and boyfriends, she believes herself to be superstar, on the level of those Kardashian chicks whose reality show plays on a constant loop on her home television. After all, she's the one that got away -- the girl that escaped the crushing boredom of a small-town existence for a life of freedom in the big city. Now she wants to bestow that same gift upon someone else, specifically her old boyfriend Buddy (Patrick Wilson), who has just had a baby girl with his wife, Beth (Elizabeth Reaser).

So Mavis tosses her overnight bag and tiny dog into the backseat of her crappy car and sets off for Mercury, where she books a room at the town's lone chain hotel and launches her mission to steal Buddy back from the new women in his life. She also unexpectedly reconnects with her class's most popular outcast Matt (Patton Oswalt), who was so widely reviled in high school that a group of jocks actually shattered his leg with a tire iron under the mistaken impression that he was gay. (Since he wasn't actually gay, the courts ruled that the assault couldn't be prosecuted as a hate crime, so the perpetrators got off with a light slap on the wrist, while Matt was sentenced to going through life with a leg brace.) And throughout Mavis' homecoming, she's gathering material for the final Waverly Prep book, constantly dodging calls from her editor wondering where the overdue pages are.

With its pathological pseudo-protagonist and biting sense of humor, Young Adult may be the year's meanest studio movie and I mean that as a compliment. Frankly, I wasn't sure that Reitman had this kind of film in him, considering how Thank You For Smoking, Juno and Up in the Air started off effectively edgy before melting into mush. But in Mavis, he and Cody have hit upon a character that they can't (and don't try) to tame or redeem. Theron throws herself into the role with fearless abandon; I know she won an Oscar for Monster, but this is by far her best performance to date. In her hands, Mavis emerges not as some broad bitchy caricature like Cameron Diaz in Bad Teacher or Rachel McAdams in Mean Girls (as funny as those women were in those roles) or a poor delusional victim, but rather as the proud architect of her own inevitable self-destruction. Even when she's on the cusp of achieving some kind of breakthrough, she quickly retreats back to her preferred view of the world and her place in it.

Theron is backed up quite well by Oswalt, whose performance as a quick-witted, overweight nerd is more in his wheelhouse than, say, the character he played in the sadly underseen Big Fan, but nicely judged nonetheless. Cody thankfully tamps down on the "Diablo-isms" that quickly turned Juno into a walking punchline ("Honest to blog," anyone?), while behind the camera Reitman does some intriguing things with the movie's point of view, occasionally filming Mavis from the perspective of the other characters, who regard her as if she's an alien that's turned up in her midst. (In fact, it's easy to imagine an alternate cut of the film where the residents of Mercury are the stars and Mavis is the hurricane that sweeps into town, upsetting their relaxed way of life.) And did I mention that the movie is hilarious? Well it is -- that terrific kind of dark humor that gets you laughing and cringing at the same time. Never mind what those Girl With the Dragon Tattoo trailers say -- Young Adult is the real feel bad movie of the holiday season and all the better for it.

Click here to read the cast and crew of Young Adult discuss the making of the film.

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