A fantastic robot metropolis situated on an alien planet is in trouble. Several wolf beings are attacking the city under the guidance of a strange robot, which does not seem to know the Laws of Robotica. Derec is bound for the robotic city by a disconcerting microchip infection in his blood. His mission is to confront this unusual robot, who does not exactly understand human beings, whose orders it must obey by virtue of the Laws of Robotica.