Clara and the Doctor learn from each other. While the Doctor struggles to understand the importance of an individual life, Clara seeks to comprehend the need to preserve and protect the world or even the universe as a whole. Yet they are both susceptible to mimicking each others flaws. The Doctor allows his desire to continue traveling with Clara to override his concern for her lies. Clara allows her need for control and the thrill of power to mask the suffering surrounding her. The invaders reaction at the discovery of a new plane of existence is small-minded. They dissect the humans they capture, unwilling to see them as more than a pile of interesting parts. They are an army seeking to conquer what they do not understand. Willful ignorance is a terrifying maker of monsters.