I AM SAM ***

His bravura turn, as a gentle soul striving to overcome prejudice and suspicion, anchors the film, and provides an otherwise routine melodrama with a strong emotional heart.

Sam Dawson (Penn) works part-time at a coffee shop to take care of his highly-intelligent young daughter Lucy (Dakota Fanning). Next door neighbour Annie (Dianne Wiest) offers help and support and occasionally baby-sits but, for the most part, Sam copes on his own.

As Lucy approaches her seventh birthday, she begins intellectually to surpass her father and social services demand she is placed in care, where she will get the love and stimulation she needs.

The girl is placed with foster parents Bill and Randy Carpenter (Will Wallace, Laura Dern), who excitedly welcome Lucy into their home.

But Sam refuses to give up his daughter without a fight and he enlists the services of attorney Rita Harrison (Michelle Pfeiffer) to argue his case in court.

I Am Sam is a showcase for Penn's incredible ability to get beneath the skin of his characters.

His portrayal of Sam is so seamless and painfully honest that it makes some of the film's more clichd moments far easier to swallow.

Seven-year-old newcomer Fanning is an absolute revelation - you can't tear your eyes off her when she is on screen and she matches Penn tear for tear. Refreshingly, she is neither precocious nor winsome and exudes an easiness in front of the camera belying her tender age.

Sadly, Pfeiffer is too light-weight to carry her pivotal role and she fails to win any sympathy with her character's own personal problems.

Her inability to shed a single genuine tear during the film's most moving scene is horribly distracting.

The courtroom finale should have audiences cheering in the aisles: take tissues, you may get through the whole box.