The film, based on the book, (and hopefully very close as I could not find much on the book that wasn't in spanish) is set in Madrid in 1939 during the last days of the Spanish civil war. It is based on a set of true events where it looks at the fate of 13 women fighting for their ideals in the aftermath. Virtudes and Carmen encourage their neighbors to keep faith in the republic, but the entry of Franco's troops stumps that and many flee.

Julia and her friend Adelina spend a night at a nightclub. One of the last bombings of the city takes place and they befriend Bianca, whose husband Enrique is the leader of the band they were listening to earlier. Later on, canepa, who was one of the musicians and also a Republican militian, decides to flee for his life. Bianca gives him money to help him. Julia starts a relationship with a soldier named Perico.

Rumours said that there was a plot to assasinate Franco. The girls are targeted for propogandistic leftist activities. Julia is the first to be arrested and is tortured under the orders of Fontenia, the officer in charge of interrogations. Adelina is turned in by her father as he believes that she is wanted for nothing but questioninf. Canepa and Teo are caught and turtured. Canepa suicides, but Teo is released on the condition she turns everyone else in. Everyone is caught except Carmen, who discovers Teo's betrayal, but she is caught as well. After lots of torturing the women are sent to a prison.

The reunion of these girls consoles them, and their behavior earns the respect of those in charge. However the situation gets worse when they join a protest refusing to sing praises to Franco. When an innocent woman and two officers are killed by leftists, 48 men and 13 women are executed as a punishment, even though they had nothing to do with it. Carmen is the only survivor, listening to the shots that killed her friends.