Start the Oscar buzz now for the dependably superb Laura Linney, who brings beauty and a tough core of intelligence and wit to the role of New Yorker Louise Harrington, an admissions officer at Columbia's graduate school of fine arts. After divorcing her skirt-chasing husband, Peter (Gabriel Byrne), Louise, 39, has few romantic illusions. But no sooner does the brash art student F. Scott Feinstadt (Topher Grace) enter her office than she's whisking him off to bed. It's not a nympho attack. Scott looks just like another Scott, her first love, who died before her best friend, Missy (sassy Marcia Gay Harden), could steal him away. No need to reveal more, except that director Dylan Kidd, making good on the promise of his 2002 debut with Roger Dodger, delivers a sexy, funny surprise package that resonates with long-buried emotions. Grace, away from the sitcom slick of That '70s Show, shows killer charm and rare sensitivity. But P.S., adapted from Helen Schulman's novel, is Linney's show, and she makes it hilarious and haunting.