Only one Robita remains, one working on the Moon for Acetylene Lamp, a space transport officer. Robita tells him he feels human, and is sure about that. Lamp, revolted by a robot having such idea, tells him that he couldn't be unless he proved himself, such as killing him for treating him like a slave. Robita does so, in an indirect way, and is left alone on the moon, crying over his guilt, until he is found one day by wandering scientist Dr. Saruta, who takes him under his wing as his assistant.