In the Cordilleras, the ride that began at the Rio de la Plata comes to an end. In the wild Gran Chaco, the heroes find themselves in an uncomfortable situation. Later, they encounter the mysterious "Viejo Desierto." The search for the criminal Sendador ultimately leads them high up into the Bolivian Andes. This story is set in the early 1870s. "In the Cordilleras" is the continuation of Volume 12 "At the Rio de la Plata." Volumes 12 and 13 are available as a book, audiobook, and eBook.