After her mother, Maria, passes away, Rosa, a young Spanish woman, discovers the secret of her biological roots in one of her mother's old letters. The letter recounts how Maria fell in love with Rosa's father, Choaib, who was one of the many young Moroccan soldiers (known as the Regulares) forced to fight alongside General Francisco Franco's troops in the Spanish Civil War. Rosa journeys to Morocco to meet her paternal family and discovers the reasons for her father's death.