Both Patria and Maria Teresa are heavily influenced by their revolutionary sister Minerva, as well as by all of the suffering they witness as a result of Trujillo's police state. While all three sisters start out innocently uninvolved in either political criticisms or the insurgence against Trujillo, as the novel progresses, all three become more heavily involved. Both Patria and Maria Teresa particularly become more heavily involved in the insurgence due to Minerva's influence.
Towards the beginning of the novel, all three sisters who are later killed by Trujillo's henchmen, enroll in school, leaving behind Dede, the youngest and surviving sister. Minerva is the first to begin understanding the evil of Trujillo's regime due to her friend Sinita who tells her Trujillo had her brother and three uncles murdered. Later, Maria Teresa becomes aware that Minerva is sneaking out of school, and she covers for Minerva, confirming to the administrators that Minerva goes to see a sick uncle. Then, Minerva confesses to Maria Teresa that she is sneaking out to attend meetings in the house of Don Horacio, an aged man who is organizing a political insurgence against Trujillo but also one Trujillo does not see as a legitimate threat due to his age. This is the moment of Maria Teresa's awakening. She had been under the impression that their country, the Dominican Republic, was free but now learned from Minerva about all of Trujillo's corruption and brutality. However, after this awakening, Maria Teresa remains uninvolved until, while in college, she intercepts a delivery to Minerva from a man named Palomino who is involved in the underground insurgence movement. At this moment, she also learns that Minerva is equally involved in the movement, and since Maria Teresa feels attracted to Palomino, when asked, she says that she too is involved in the movement. From that moment on, she begins actively helping her sister and the movement, showing us that Maria Teresa changed during the course of the novel from being one who was relatively innocent of the knowledge of Trujillo's cruelty to one who became actively involved in the insurgence.
Patria likewise started out being fairly innocent and naive, even more so than Maria Teresa. Patria starts out being very religiously devout and even considers becoming a nun, until she falls in love with a man named Pedrito Gonzalez whom she marries. She gives birth to two children but then miscarries the third, a miscarriage that leads to a loss of faith and a political awakening. Her own suffering from the loss of her child opens her eyes to see all of the suffering being endured by her entire country under Trujillo's regime. However, while aware of the need for reform, she does not become actively involved like her two sisters until much later. It's not until she has been married for 18 years, in 1959, that she begins to envy the active lives of her sisters. She, like her sisters, celebrate the night they learn that Cuban dictator Batista has fled Cuba, an event that the people of the Dominican Republic take as a good sign of liberation. After that, she begins getting involved with her sisters in the underground movement, such as allowing the members to meet secretly on her property. Finally, while at a religious retreat in Costanza, she witnesses a boy being shot in a rebel fight, and fearing for the safety of her own children, decides to become actively involved in the movement. Hence, like Maria Teresa, though Patria's character starts out as being innocent, naive, and even devoutly religious, as she witnesses her sisters' involvement in the underground insurgency movement and all of the atrocities taking place under Trujillo's regime, she too progresses into a political activist. As each sister becomes more and more involved in the underground movement, their fate becomes more and more evident; they will eventually be murdered as insurgents by Trujillo's henchmen, just as Minerva prophecies earlier on in the novel, “Something has started that none of us can stop" (Part II).