Almost every time Julia Roberts gets involved in a movie project that has even slightly higher ambitions than her breakthrough hit, Pretty Woman, it's been an occasion to head for the hills. (And no, The Player doesn't count — she's in it for barely more than a minute and she plays herself.) Two words come to mind: Mary Reilly. Well, now Roberts has a two-word answer for those two words, and whatever other words critics and non-fans might want to use against her: Erin Brockovich. Roberts rules in the title role in this fact-based legal drama about a struggling single mom who bullies her way into a job at a small-time law firm and, through an uncanny combination of pluck, major attitude, quick-wittedness, and sheer doggedness, pulls off the biggest cash settlement in a direct-action lawsuit in the history of these United States. In a lot of respects this is a very old-fashioned Hollywood entertainment — Pretty Woman (you won't believe some of the outfits Roberts wears here, by the way) meets Norma Rae. Well, what do you want from Roberts, a remake of Persona? (No. You don't. You really don't.) In any case, this also happens to be a remarkably satisfying Hollywood entertainment, one that's been superbly structured and engineered by screenwriter Susannah Grant and director Steven Soderbergh.

After almost scaring the bejesus out of Ed Masry (Albert Finney), the lawyer who lost her personal-injury case, Brockovich is subsequently hired by him. But as she is filing away at his firm, she gets a little confused as to why there are medical records mixed up in a real estate case. She starts to dig, and uncovers a toxic-waste incident that has literally poisoned an entire town. Thus begins a long crusade that will, of course, redefine Brockovich while creating a number of conflicts in her home life (including the alienation of her oldest son and her gentle biker boyfriend, played by Aaron Eckhart) before ending in triumph. Grant and Soderbergh take this material and mix things up a little, digging for emotional truth and underplaying a number of scenes that could have easily been done Rocky style. Soderbergh turns down the volume on his usual stylistic flourishes (which worked so well in his last picture, The Limey) but still manages to retain a relatively idiosyncratic tone — aided immeasurably by the sometimes almost-burned-out tones that cinematographer Ed Lachman brings to the movie's parched California landscapes.

The best testament to Soderbergh's knowingness as a director is the way he handles Roberts. This star's got a problem: No matter how skillfully she performs — and here she does arguably her best work ever — she's still Julia Roberts. This was the central joke of the odious Notting Hill, which considered the dilemma a cause for celebration. What Soderbergh and his supporting cast do here is create a vivid, plausible, engaging world for Roberts to interact heroically with, whether she's feeling the pain of a woman who's just had her uterus removed or throwing shade at a hopelessly uptight lawyer whose lack of empathy is threatening to steer the whole case off its rails. Soderbergh grounds the movie in some very subtle ways, such as starting off one of the many scenes in which Brockovich storms into Masry's office by showing Masry having a strangely sheepish personal phone conversation. The camera lingers on him a little longer than needed, which makes it more than just a funny "bit." As for the supporting cast, it simply can't be praised enough. Finney is pure genius — sly, crusty, put-upon, and genuinely lovable as he learns as much from Erin as she does from him. Eckhart, almost unrecognizable in a beard and long hair, is wonderfully resonant as a sweetheart of a guy trying to work through a situation in which he feels like he's being abandoned but knows that that's really not the case. And Marg Helgenberger, as one of the most initially deluded and eventually devastated victims of the case, is luminous and quietly heartbreaking. They all conspire to make Erin Brockovich not just a triumph for Roberts, but a triumph of mainstream moviemaking.