Socorro (67) is an stubborn lawyer in the twilight of her life obsessed with the idea of finding the soldier that killed her brother back in 1968 during the infamous "Tlatelolco massacre". This obsession has affected her relationship with her sister Esperanza (70) and her son Jorge (45). Suddenly, she receives the missing clue to locate the military man and decides to carry out an absurd operation to avenge the death of her brother risking her legacy, her family, and her own life.