An American engineer working on a dam project in Brazil loses his seven-year-old son in the rain forest to an isolated Indian tribe, and spends the next ten years in a tireless search. The film's ultimate message - that we continue to destroy this hot house at our peril -is the uncomfortable truth to which he returns in a final caption. What lies between is a half-fantasised view of Indian tribal culture, with its peculiar codes of existence and bewildering intimacy with nature. For despite some flamboyant violence, this is less the despairing Boorman of Deliverance than the unabashed visionary who twisted The Exorcist into its over-ambitious sequel. The forest scenery is ravishingly photographed, and the sheer visual sweep more than compensates for some occasionally shaky acting. Full marks, too, for giving us subtitles for the Indian language; as an ethnographic adventure, there is more to these decorated natives than Mad Max Factor. A rare delight.