After two years of military training in Brazil and Cuba, Sara Castillo, a member of the Chilean Revolutionary Left Movement (M.I.R.) returns to Chile in 1980 with the intention of contributing to the overthrow of the Chilean dictator General Augusto Pinochet and his military junta. She plans to build a bomb and detonate it at the Santiago Stock Exchange during a visit by the top military officers of the Chilean Secret Police.
While building the bomb Sara goes to watch a football match at the National Stadium of Chile in Santiago. At the game she meets an old friend of hers, Paula Martinez, who invites her to visit her and gives Sara her address on a piece of paper.
Sara builds the bomb but while travelling to the Stock Exchange to place the bomb, it detonates prematurely in the Santiago CBD, killing her and killing and injuring a number of civilians. During the ensuing Secret Police investigation the note with Paula Martinez's address on it is discovered in Sara's shack at the Raul Silva shanty town in Santiago.
Paula is arrested as a suspected accomplice of Sara Castillo and brutally tortured by two members of the Secret Police, Captain Armando Castro and Captain Carlos Alvarez but is eventually released. Paula swears revenge on the two police officers.
But how can Paula possibly take on the might of "Pinochet's Gestapo" and achieve the revenge that she needs?

"Nothing is more costly, nothing is more sterile, than vengeance." - Winston S. Churchill