-The United States has lost much of its former glory and, at the very least, its southwest region has been reduced to poverty and "Third World" status. El Patrón claims that just as many people try to run to Aztlán from the United States as the other way around. It is mentioned briefly that Nigeria is now one of the richest countries in the world, effectively usurping US prestige as one of the world's wealthiest nations -Formerly known as Mexico, Aztlán lies south of the border region, comprising Opium and other unnamed states. As evidenced by conditions in one of the major cities, San Luis, parts of Aztlán are very affluent, while others, such as Durango, the region that El Patrón and Celia hail from, languish in poverty. While many residents of Aztlán still try to cross Opium and get to the United States, a similar number of US immigrants try to enter Aztlán illegally. Certain regions along the coast of the Gulf of California in Aztlán are desertified, and what remains of the Colorado River has become highly polluted. -A large city, San Luis boasts a mostly affluent population, and is indicated to be a major cultural center in Aztlán. It is the location of the convent school that the Mendoza girls attend, and the Keepers' plankton factory is located about 5–10 miles outside the city limits. Matt, Chacho, Fidelito and Ton-Ton later venture to San Luis in search of the convent where Tam Lin told Matt he would find María, arriving in the midst of the Dia de los Muertos festivities. However, they are confronted by the Keepers. Fortunately, the intervention of the nuns and María's powerful mother, Esperanza Mendoza, saves the boys from being taken away by the Keepers, and, subsequently, after Matt sees María, Esperanza recruits him to undertake the task of breaching Opium's security and gaining control of the country.