The Amazon rain forest is a living laboratory for Dr. Robert Campbell (Sean Connery), a reclusive research scientist living with a Brazilian native tribe. Campbell has accidentally discovered a flower extract that cures cancer, but has been unable to duplicate the formula. With the assistance of Dr. Crane (Lorraine Bracco), he explores every possible chemical derivative, but continues to fail. When a child in the village is near death from a tumor pressing against his trachea, Campbell and Crane stand against each other on the moral issue to use the last of the successful serum to save him or to keep it for further analysis. At the last moment, Crane reconsiders, and agrees to save the child. At the same time, commercial loggers begin to creep ever closer to the village, and government officials demand the tribe's relocation. With only yards remaining between the bulldozers and the tribe, Campbell discovers a vital clue to the elusive elixir he seeks. His attempt to stop the workmen results in violence and a raging forest fire which destroys his lab equipment and the natives' village. The story ends with Campbell, Crane, and the tribe pushing deeper into the jungle in search of new answers.
In a change of pace from his usual action film fare, the skilled work of director John McTiernan brings emotional depth to what would otherwise be just another pro-environmental propaganda film. Connery, who had starred in McTiernan's crowd-pleasing 1989 film The Hunt for Red October, gives a convincing performance as the determined and complex researcher haunted by mistakes of the past. Bracco's character adds the realistic humor of the city scientist adjusting to Spartan life in the trees, but she does so with both strength and dignity. The constant bickering of two equally obstinate scientists gives a mild "honeymooners in the jungle" quality. Filmed in the Mexican rain forest, the canopy is captured in breathtaking cinematography.