You will see here the breathtaking Iguazu Falls of South America and its magnificent environment of lush green forest. This movie became number one in the Church Times listing of Best Religious Films of all time. The area where the Guarani tribe is located is in the jungle of Paraguay which was under the protection of Spain, hence, Jesuit missionaries are safe, but when the Treaty of Madrid (dividing the land in South America between Spain and Portugal) was signed, this territory was transferred to Portugal whose monarch disapproved the idea of the mission.
Soon conflict erupted as the Jesuits fought hard to defend the Guarani from the Portuguese who wanted to drive the tribe out of the jungle for the gold reserve in the area. The next scene revealed how the missionaries struggled to keep the tribe safe while devotedly adhered to the sanctity of their mission. The Church failed to save the missionaries and yielded to the pressure imposed by Portuguese crown, in the end all the missionaries were killed.
According to the book of Chris Lowney, Heroic Leadership, this was the most daring mission done by the Jesuits in an attempt to spread Catholicism to the world. Very awesome movie, you gotta watch it!