The recurring team of Powell and Donovan are in charge of field tests on an asteroid mining station with a robot, DV-5 (Dave). But the robot stops producing ore, and cannot explain why. The robot is a new model with six subsidiary robots under its control (they are described as fingers) via positronic fields, a means of transmission not yet fully understood by roboticists. When they secretly observe the robot, it starts performing strange marches and dances with its subsidiaries whenever something unexpected happens. It is up to the two field testers to figure out why Dave is acting the way he is.
This observation-dependent behavior alteration, hindering the resolution of the robots' behavioral bug, makes it an early example of a Heisenbug (software problem)[original research?]. The reason is that the main robot had too many subsidiary robots under his control, and whenever there is a serious need of decisiveness, his brain overloads, so whenever there is a dangerous decision to be made, the pressure increases, and he breaks down. The other robots do not know why they are dancing and when interrogated one mentioned that they received an order but before they could get it the order was replaced by an order to dance. Powell and Donovan spend days watching them on the telescreen, then follow them to find out what the original order was till they realize it doesn't matter when they are trapped in a cave-in when trying to stimulate the dancing from the robots. Why did the robots stop dancing when the humans were watching them?
Because when the humans were around, the pressure is lifted somewhat, because the human's presence helps the robot's mind make decisions. They then destroy one of the subsidiary robots, allowing Dave to no longer be confused, and as he can now hear them, the First Law of Robotics takes over ("Through action or inaction, a robot cannot allow a human to come to harm") and he rescues them from danger.