Sulu wants Uhura for something.

An evil mass-murdering robot? Why, it must be time for “The Changeling”, which tries to answer the question “what would happen if a robot could feel sad?” and kind of succeeds. “Mirror, Mirror” tries to answer the question “what if the Federation were the kind of organization that built mass-murdering robots?” and also kind of succeeds. Also! A bonus discussion about Deep Space Nine.