Mariana is 42 years old, and a member of the Chilean upper class that takes privilege for granted. Scorned by her father and neglected by her husband, Mariana occupies her days with fertility treatments, running an art gallery and learning to ride a horse. Her riding instructor, a former cavalry officer known as The Colonel, is under investigation for human rights abuses committed decades before. When Mariana grows closer to her enigmatic teacher, she's directly confronted with the outrages of the dictatorship for the first time, and her increasing interest threatens to tear down the invisible walls protecting her family from the past.