Data loses his memory on a pre-industrial world.
Data crashes on a primitive planet and loses his memory after a mishap. The local people, who are at an early stage of technology, find him and take him in. Without his usual abilities, Data tries to adapt to a life as a stranger, while a dangerous radioactive object he carried begins to harm the villagers.
Meanwhile, back on the Enterprise, Troi is working to complete the exam for the rank of commander, a bridge-officer test. The episode is a thoughtful pair of stories on identity and responsibility. It is a gentle story that features Data in a humane light, and it shows how Troi progresses in her career.