The Queen of the Pánuco is the story of a Mexican Federal Policeman once tasked with protecting the President of Mexico Lázaro Cárdenas, but now disgraced for petty theft. He and his wife Mariana travel to the oil port Tampico on the Mexican Gulf Coast, looking for their estranged son Rey, where they stumble into the struggles between Socialist petroleum workers and those who would suppress them to the point of assassination. All this, on the eve of the expropiation of Mexican oil by Lázaro Cárdenas in 1938 and the Second World War. Complicating the situation, Rey turns out to be a lawyer who protects workers' rights and is married to a passionate young Irish woman who has fled Madrid and the on-going Spanish Civil War, where she took fateful measures to protected non-fascist militia women from rightist urban attacks and predations by supposedly helping Soviet co-fighters.