Diane Lang, a professor of German from Yale, came to Paraguay to conduct research on the Mennonite settlements in the green hell called the Chaco. Walter Stanek, a hydrogeologist from Arizona, was in country for what he thought was a disaster-prevention project in Asunción and an environmental impact study for the proposed Corpus dam on the Paraná river. So how did they get caught between rebel forces and the secret police under Colonel Hector Ibarras, a man with designs on power? It all started with an encounter at the Club Bahia Negra and a late night attack on the dusty, unpaved road of a nearby shantytown—and it ended with the two Americans struggling to survive while forced to play a pivotal role in a plot to overthrow the government of General Enrico Zancon.