A trip on board the Oswaldo Cruz, cruising the Amazon to bring medical aid to the most remote villages. The Brazilian warship Oswaldo Cruz is on a peaceful mission. Its holds are crammed with medical equipment : a pile of drugs, bandages, dentist's chairs, even a mobile operating theatre. On board the hospital ship are three young doctors. They have decided to spend a year providing medical assistance to remote villages in Amazonia. They know that, as well as health care, their work will also consist of educating the villagers on hygiene and nutrition.