American Fable is ambitious, maybe too much so sometimes, but there's an intense pleasure in the boldness of the film's style.
It might have been impossible to convert "Agnes of God" from a play into a movie under any circumstances, since the intrinsic reality of film throws the play's conceits and contrivances into sharp relief. Speeches that seemed stylishly theatrical on stage seem, in screen close ups, to be. . . merely theatrical. But that's just the beginning of this film's problems. It considers, or pretends to consider, some of the most basic questions of human morality and treats them on the level of "Nancy Drew and the Secret of the Old Convent."
The story: A dead baby is found in a lonely convent, where the nuns lead a sequestered life and there are no men who possibly could have been the father - unless you count poor old Father Metineau, the nuns' spiritual adviser, who has a drinking problem. The police investigation indicates that the baby's mother, and possibly its murderer, was Sister Agnes (Meg Tilly), a young, simple-minded girl of total naivete. It is never made quite clear what specific problem Sister Agnes suffers from, but she clearly has parts on order.
A psychiatrist (Jane Fonda) is assigned to the case and it quickly becomes clear that she will learn little from Sister Agnes, who has total amnesia regarding the entire incident. The convent's mother superior (Anne Bancroft) at first seems more helpful - she is a "modern" woman who was married before she entered the convent and who shares a forbidden cigarette with Fonda - but she, too, turns hostile as the investigation continues.
I will be giving away no essential secrets if I reveal that the precise details of the conception, birth and murder of the child are never cleared up to anybody's satisfaction.