A documentary reenactment of the government-ordered massacre of striking tin miners and their families at the Siglo XX Mines in 1967 in Bolivia.

The film starts with previous massacres and represions (starting 1942 in Catavi), before and after the bolivian Revolution, and puts the finger on the people responsible. All of this according to the director's belief of movies having to show what people wanted: and people wanted to know causes and responsibilities. A little reading on the history of Bolivia after the revolution should led to a better understanding of this film, for it was directed to people who actually lived the process (some of them acting in the movie), and many meaningful sequences and details may not be understood in all their symbolic and historic value.