If her single-mindedness occasionally lapses into boorishness for dramatic impact, the overall effect of Roberts' transformation is extremely satisfying. She truly grasps this role, portraying a self-centred but courageous individual with a tender heart.

Erin Brockovich may have a volatile relationship with everyone she encounters, friend or foe, but she is totally driven in her quest for truth. Her true depth lies in her identification with her firm's clients, individuals blighted with appalling cancers brought about by their unwitting exposure to toxicity. Her affinity is in stark contrast to the professional lawyers who join the case later in the proceedings.

Aaron Eckhart is excellent as Erin's boyfriend, a long-haired, tattooed biker who is cuddly as a teddy bear with her 3 kids. But even he has his limits.

Albert Finney puts in a seamlessly accurate portrayal as Ed Masny, a grizzled attorney who has suffered a quadruple by-pass, but is, in his own way, just as driven as Erin.

The actual court case, that the Pacific Gas and Electric corporation have been poisoning land with Chromium 6, and that there is ample evidence to prove this, seems cast-iron. The film succeeds in thwarting Erin's professional efforts with red tape, and her personal life with a boyfriend who genuinely cares for her children, but who cannot cope with the demands of her investigation. This ensures dramatic tension right up to the conclusion.

Hope catches on amongst California's lower-class sprawl. The settings are entirely plausible, and Erin's singularly average family life is a good counterbalance to the world of multi-million lawsuits. The only real contrivance seemed to be the offices of the water board where she goes to ferret out archive information. A spectacularly gormless young man, twitching away like a TV Movie serial killer, is entranced by her cleavage into letting her rummage freely through all the files.

It is intensely gratifying when a 28 billion-dollar corporation is humiliated by the sheer belief of one woman who would be dismissed by her legal superiors as 'white trash'.

Erin Brockovich is an excellent entertaining study of one woman's determined battle against the odds. Julia Roberts demonstrates how far she has come since rocketing to superstardom playing a pretty hooker.