After two years of active resistance, in 1998, the people of Mehuin in southern Chile succeeded in stopping the construction of a pipeline that would have spewed industrial waste from the largest pulp mill under construction in South America into Maiquillahue Bay. This article analyzes the power of the Defense Committee of Mehuin's discourse in mobilizing the people. The outcome of this conflict illustrates the committee's ability to connect the pipeline's threat with local transcendental meanings, while scientifically explaining the pipeline's ecological impact. Thus, residents could make sense of the danger in the context of their culture, be motivated to defend the bay, and also have their understanding of nature transformed. The case suggests that local communities may engage in a symbiotic and scientifically informed relation to nature and become wardens of their environment. (Environmental conflict, Chile, scientific and religious knowledge, political ecology) ********** The projected construction of a pipeline for the discharge of industrial waste was a turning point for the people of in Chile. In an unprecedented case starting in 1996 and extending for two years, the local community challenged and defeated COPEC, the largest Chilean holding company. Contrary to national and regional expectations, a handful of rural villagers proved capable of better safeguarding nature than the national environmental laws. Their success preserved their environment and their economy. The successful defense of Maiquillahue Bay demonstrates how local residents were able to create a discourse that allowed no dissent among them and made any negotiation with the corporation impossible. Based on documents from the days of the conflict and on interviews and group discussions, this article analyzes the discourse of the Defense Committee of a committee created to stop the construction of the pipeline. The victory is a tribute to the people's ability to apply a transcendental meaning shared by different groups that populate the area to mobilize against the ominous threat. The pipeline came to be known as fatidic, ducto fatidico, the fatal (or fated) pipeline, a term that became an icon unifying the community in its struggle. The Defense Committee's discourse incorporated the various views in including those of fishermen, small business people, indigenous and other residents, and Catholic and Pentecostal believers. In so doing, the committee integrated local practical knowledge, religious views, and scientific concepts. As rural and indigenous inhabitants of the countryside, the residents were regarded as naive and easy to manipulate. They were, instead, capable of describing the unique maritime and fluvial aquatic populations of the Lingue River and Maiquillahue Bay. In describing the effect of industrial residues, they alluded to the role winds and tides have in disseminating pollutants. They also understood the chemical composition of chloride residues and the time it takes the bay to renew its water. They contended that most local species would die from the chloride. This was not traditional knowledge, and the committee supported its arguments with scientific documents. The use of scientific language by Mehuin's community leaders attracted national attention. In the October 16, 1996, edition of the national newspaper La Segunda, a surprised journalist wrote about reports by marine biologists, wind studies, and even aerial photographs has this woman [Teresa Castro; see below] repudiating the project. The residents realized that they needed scientific knowledge, but the acquisition of new knowledge did not erase or replace existing cultural understanding. The power of the discourse to mobilize the community was tested in two major events: the visit of Greenpeace's ship, Rainbow Warrior, and the Naval Combat of Mehuin, as it came to be known. The former took place on November 25, 1996, and set the stage for the community to display its unity. …