2044. The Earth’s population has decreased to 21 million people after a natural disaster. The most of the land has turned into a radioactive desert. The survivor are finding shelter behind high walls and artificial clouds created with the help of robots called Pilgrims. The ROC corporation has designed and built robots that maintain the existence of remaining cities. All the robots are equipped with a protective mechanism not allowing them to hurt people. After one incident, an insurance agent Jacq Vaucan realizes that robots have learned to change themselves.