The eccentric scientist, Dr. Robert Campbell (played by Sean Connery), has been living in the Amazon jungle for years, studying the medicinal properties of plants and working on finding a cure for cancer. When his latest breakthrough requires the use of a gas chromatograph, he sends for a research assistant to help him. However, when Dr. Rae Crane (played by Lorraine Bracco) arrives and he realizes she is a woman, he is initially dismissive of her abilities.
As they work together, Dr. Campbell and Dr. Crane clash over their different approaches to research, with Dr. Campbell favoring a more intuitive, hands-on method and Dr. Crane adhering strictly to scientific protocol. However, they eventually start to appreciate each other's strengths and insights, and begin to make progress in their research.
However, their work is threatened when a large drug company sends bulldozers to the area where they are conducting their research, in order to build a road through the jungle. Dr. Campbell and Dr. Crane team up to try to prevent the destruction of the plants they are studying and the disruption of the delicate ecosystem of the jungle.
As they work together to save their research, Dr. Campbell and Dr. Crane begin to fall in love. However, their burgeoning relationship is complicated by Dr. Campbell's reluctance to accept help from anyone, and his fear of risking failure in his quest to find a cure for cancer.
In the end, Dr. Campbell and Dr. Crane are able to save their research and the jungle, and make progress towards finding a cure for cancer. They also find happiness together, as Dr. Campbell learns to trust and rely on Dr. Crane.