"Relativity," the alluring new romantic comedy-drama from executive producers Marshall Herskovitz and Ed Zwick, has many charms of its own to recommend it. But fans of Herskovitz and Zwick's miraculous "My So-Called Life" -- cut down prematurely by low ratings -- might find one aspect of "Relativity" particularly charming. Squint a little, and "Relativity" becomes a surrogate "MSCL," satisfying our curiosity about the destiny of Angela Chase, that show's endearingly introspective teenaged heroine. You see, Angela could have grown up to be "Relativity's" Isabel Lukens, or a woman very much like her. In the September 24 pilot of "Relativity" (10 p.m., ABC; it will be regularly seen at 10 p.m. Saturdays beginning September 28), 24-year-old Isabel (Kimberly Williams) has run off to Rome to ponder -- or escape -- the marriage proposal she's just received from her boring, controlling, CD ROM-designer boyfriend back in Los Angeles (think "My So-Called Life's" Brian Krakow as an adult). In the opening scenes, she wanders around Rome shedding copious tears, but she's too girl-next-door-ish (Williams played Steve Martin's daughter in the two "Father of the Bride" movies, but don't hold that against her, she's perfect here), too relentlessly American in her leather jacket with her L.A. Clippers cap dangling from her designer backpack, to register as truly tragic. Like Angela, she's absorbed in a not-completely-unpleasant romantic mess of her own making. Isabel's problems (like Angela's) are the problems of privilege. She's a nice suburban girl with all the comforts upper middle-class parents can provide (including a ticket to Rome), but she wants to be a little less comfortable. She wants to be wild and special. As we know from "My So-Called Life," the Angelas of the world are unusually susceptible to tender bad-boy types -- Angela's was named Jordan Catalano. And the Isabels are susceptible, too. In "Relativity," Isabel's Jordan is Leo Roth (newcomer David Conrad), a 26-year-old aspiring artist from L.A. -- her own backyard -- who's also in Rome to sort out his life. Leo is scruffy and beautiful and vulnerable and slightly dangerous like Angela's Jordan, except he's a man, not a boy, and he sees Isabel; he doesn't look past her. He knows her worth immediately. He asks her why she's crying; they walk around the Eternal City for hours; she snuffles on about her ambivalence toward marriage while, ever the good girl, sending out proper (if half-hearted) platonic vibes: "I'm involved. I have this whole -- involvement." But the light is golden and Leo is dreamy and Isabel falls. Wouldn't you? Next page: Unmarried...with parents.