The breezy trailers for _Stepmom_ would lead one to believe that it is one of those light films one would expect from director Chris Columbus. The reality of the film, so cleverly hidden in the rushes, is much more sober and serious. Some would go so far as to call it sad. But it doesn't go quite _that_ far, in my opinion. _Stepmom_ is a well-made and undeniably involving film, but its artistic compromises are not completely effective.

The character being referred to by the title actually is not a stepmother, at least not yet. She's Isabel Kelly (Julia Roberts) the much younger live-in girlfriend of Luke Harrison (Ed Harris). Luke's two children, 7-year-old Ben (Liam Aiken) and especially 12-year-old Anna (Jena Malone) are resentful of Isabel, and somewhat rightfully so--they have been blessed (spoiled?) with a perfect mother, Luke's ex-wife Jackie (Susan Sarandon). Although busy professional photographer Isabel scarcely has the time or interest for parenting, the kids are occasionally left in her questionable care, creating even more points of conflict between the two women.

About the first hour of _Stepmom_ has a nice hard edge, albeit somewhat overwritten by the five credited scripters, Gigi Levangie, Jessie Nelson, Steven Rogers, Karen Leigh Hopkins, and Ron Bass. (I'm not so sure a girl Anna's can come up with such pithy zingers so quickly; it's one thing to be a smartass, and quite another to be a smart ass.) Even during the seemingly happier moments, there's a palpable undercurrent of tension, especially between Isabel and Jackie. Their conflicts over parenting philosophies and authority is something not often seen in film, and it's solidly played by Roberts and Sarandon.

Columbus is not known for displaying a hard edge, if even one at all, and so the air of anger cannot last--or, at the very least, must tone down somewhat. And that it does, in a less than convincing fashion. The most contrived development has Anna, who has heretofore been Isabel's most vocal detractor, make a complete 180 after Isabel shows her a nifty painting technique; before long, the two are best friends singing along to "Ain't No Mountain High Enough" in the car. But the big complication--and the film's big secret--is also a big misstep. Jackie, it is revealed, has secretly been receiving treatment for cancer, and her condition is steadily worsening toward the inevitable.

Now, I have no problem with films featuring people suffering from a terminal disease. But throughout _Stepmom_ I wondered if the illness wrinkle was really necessary. The Jackie/Isabel conflict was already involving, with each side showing its share of right and wrong; making Jackie sick unfairly stacks the sympathy deck in her favor. But I suppose the illness was a necessary compromising device for Columbus, enabling him to try something more edgy at first and then settle into familiar, safe, and blatantly calculated schmaltz, which hits full-throttle with the de rigueur mawkish mother-child "goodbye" scenes. And though this is an adult-aimed film, Columbus also couldn't completely shake his _Home_Alone_ kiddie tendencies by casting Aiken, a Macaulay-esque moppet who is as short on talent as he is long on cuteness.

Before her comeback with _My_Best_Friend's_Wedding_, Roberts was in a bit of a career bind. She wanted to prove her serious acting chops, but audiences wanted to see her megawatt smile and hear her whooping laugh, and drab, smile-less efforts such as _Mary_Reilly_ flopped. Here, Roberts attempts to have the best of both worlds, flashing those pearly whites ever so often within a meaty dramatic context. Unlike Columbus's compromise, hers works, and she delivers one of her most impassioned performances, holding her own against the formidable Sarandon, who is true to strong form. Stealing some of their thunder is the impressive Malone, who plays such a convincing brat in the earlygoing you may find yourself wanting to slap her.