Many years ago a group of cavers, among them the director’s parents, discovered the Ojo Guareña cave. Today, amid rock paintings and Civil War secrets, we follow them into absolute darkness on a journey through past and present, where time seems to have stopped. Ojo Guareña is the second largest karst cave complex on the Iberian Peninsula and one of the ten largest in the world. Guided by the beam of the adventurers’ headlamps, we enter a world under an eternal spell, home to the first hominids and a corner in which revolutionary songs were sung under Franco. A descent into the depths of the past that offers unexpected discoveries while we wonder whether we are the ones looking at the cave or whether, on the contrary, it is the cave that is watching us.