 Doug is an American mining engineer. Pres. Valdez of Paragonia (Aitken) wants him to reopen the country s mines. Doug is not interested ... until he sees the President s beautiful daughter, Juana (Rubens). Valdez returns to Paragonia, but is deposed by Generals Sanchez and Garcia and locked in San Mateo Prison. The Americano arrives. His company s local office has been ransacked, but he finds loyal caretaker Dan (Wilson) in hiding there. He is contacted by former Prime Minister Castille, now in disguise as a peddler... Valdez writes the mysterious date "23 Noviembre 1899" on scraps of paper which are then thrown from the prison window as garbage. Juana checks her father s diary. That date contains an account of a successful escape from San Mateo, using the secret tunnel! But Garcia demands that Juana marry him the next day or Valdez will die...