This is really two movies rather than onea powerfully acted account of a mother (Michelle Pfeiffer) adjusting to the loss of her kidnapped three-year-old son and an account of how, nine years later, the boy searches for his identity after his family finds him. Each movie has its strengths, but the two never quite come together. Stephen Schiff adapted the best-selling novel of Jacquelyn Mitchard, and perhaps because Pfeiffer’s own production company made the movie, he has had to devote most of his energy to reconciling a star vehicle with a different sort of work. Though director Ulu Grosbard is as good as he usually is with most of the actors, the story problems tend to stump him too. With Treat Williams, Jonathan Jackson, Whoopi Goldberg, and John Kapelos. (JR)