Cuba was the last colony of the Spanish empire. Thousands of Cubans clandestinely went to the peninsula to defend the Second Republic against the threat of fascism and Franco's coup d'état. The so-called "Pearl of the Crown", until a little more than thirty years earlier little more than thirty years earlier, threw itself into what became known as the Spanish Revolution.

What was the mystery of this relationship?

"Listening to the shadow" proposes an incisive and archaeological look through film, photographic and sound archives, most of them unpublished until now. A reflection that attempts to unveil the face and the commitment of the nameless people,those who arrived with a gleam in their eyes and were left in the shadows of history. Black holes full of light.