Who made the dams of the Ebro, Entrepeñas, Barrios de Luna and many others? Who rebuilt towns and cities like Belchite, Brunete, Oviedo, Teruel... among many other populations? Who built from airports such as Sondica or Labacolla to municipal stadiums like those of Valladolid and Palencia, to prisions like Carabanchel or Cordoba? Republicans who were prisoners condemned to work as slaves, whose only "crime" had been to defend the democratically elected legality. This documentary tries to recover the memory of these events focusing on the battalion of Republican prisoners of Fabero del Bierzo. It investigates the mechanisms of social construction of silence, fear and forgetfulness that even today can be felt where the events occurred and where the descendants of many of those prisoners still live.