Sam Dawson (Sean Penn) is a mentally-retarded adult with a seven-year-old daughter, Lucy, to look after. When Sam gets into trouble with the law, both for soliciting a prostitute and for child harassment, the authorities take Lucy away and place her in care. With the help of high-flying attorney Rita Harrison (Michelle Pfeiffer), Sam then fights to regain custody; but when things go wrong in his new job, it looks like he might lose his daughter forever.