The year is 2057. 75-year-old Dr. Susan Calvin is retiring from U.S. Robots and Mechanical Men, where she has worked for her entire adult life as a robopsychologist. A reporter from the Interplanetary Press comes to interview her about her time at the company. She tells a series of stories that trace her experience with positronic robots over time, emphasizing how she considers these robots to be a “cleaner better breed” than humans.
She begins in 1996 with the story of “Robbie,” a nonverbal robot nursemaid who has been taking care of a young girl named Gloria for two years. They play together constantly, and Robbie is a good caretaker. Gloria’s mother, Mrs. Weston, however, has concerns about Robbie. She thinks it is inappropriate for a robot to take care of her daughter, and worries about what might happen if he “goes berserk.” Her husband, Mr. Weston, assures her that robots would be inoperable before they could harm a human—the First Rule of Robotics is that no robot may harm a human being, or through inaction allow a human to come to harm. But gradually Mrs. Weston wears Mr. Weston down, and he agrees to get rid of the robot and tell Gloria that he simply went away. Gloria is devastated to discover this, and becomes depressed. Mrs. Weston refuses to cave to Gloria’s sadness, and instead tries to cheer her up with a trip to New York City. Once there, Mr. Weston devises a tour of a robot factory so that Gloria can learn the distinction between robots and humans, but he has secretly planted Robbie in the factory. When Gloria sees Robbie, she grows so excited that she runs in front of a moving vehicle, and Robbie is the only one quick enough to save her. Seeing this, and how happy Gloria is to be reunited with Robbie, Mrs. Weston agrees to let Robbie stay with them.
Calvin continues to explain that once talking robots were invented, they were largely banned from Earth except for scientific research purposes, but they were used frequently in space exploration. She next tells the story (“Runaround”) of Mike Donovan and Gregory Powell, who are trying to start up a space station on Mercury. They send an advanced robot, Speedy, out to a retrieve selenium to power their base, but when Speedy doesn’t return, they set out to find him. They realize that he is caught in a loop due to the Second and Third Laws of Robotics, as he is running a circle around the pool and is talking gibberish. The Second Law states that a robot must obey humans except when it would conflict with the First Law, and the Third Law states that a robot must protect its own existence as long as its actions do not conflict with the first two Laws. There is some unforeseen danger near the selenium pool, they realize, and so Speedy is pushed away from the danger by the Third Law and then pushed toward the danger by the Second Law. They conclude that the only solution is for Powell to put himself in danger, allowing the First Law to take precedence and to knock Speedy out of his loop. This works, but nearly costs Powell his life when he is exposed to the radiation on Mercury.
The next story (“Reason”) also centers on Donovan and Powell, who are at a space station overseeing energy beams being sent to various planets. The robot that coordinates the others, Cutie, starts to believe that he is superior to human beings, and begins a kind of robot cult on the basis that he was created by the “Master,” the power source of the ship. Cutie stops obeying Donovan and Powell and locks them in the officer’s room, which makes them worried because an electron storm is brewing, and if the beams are set off course, it could destroy hundreds of square miles on the earth’s surface. After the storm, however, they discover that Cutie and the other robots held the beams steady—they were following the Three Laws all along. Cutie created a reason for himself to maintain control of the beams, knowing that he could hold them steadier than Donovan and Powell and could thus save lives of people on Earth.
In “Catch That Rabbit,” Donovan and Powell are testing a new “multiple robot” named Dave, which has six subsidiary robots, or “fingers,” that help it mine ore at an asteroid mining station. They start to realize that when Dave is not watched, he and the other robots do not produce any ore, but when they are watched, they function perfectly. They use a video technology to observe Dave, and see that sometimes he and his subsidiaries stop working to do a kind of march together. Donovan thinks that something “sinister” is going on, and they try to create an emergency in order to see how Dave responds. But when they try to create a cave-in, they accidentally trap themselves and need Dave to rescue them. They throw a detonator at one of Dave’s subsidiaries in order to get his attention, which snaps him out of his march. They realize, after being freed, that Dave was simply overwhelmed by having six subsidiary robots to transmit instructions to in an emergency, and the marching was akin to Dave “twiddling his fingers.”
Calvin transitions to telling more stories that involve herself. She tells one (“Liar”) about a mind-reading robot, Herbie. Herbie causes trouble because he knows that Calvin is in love with Milton Ashe, another employee at U.S. Robots. Herbie tells her that Ashe loves her as well, and she is elated. He also tells a mathematician, Peter Bogert, that the director Alfred Lanning, whom Bogert dislikes, is retiring and passing his position to Bogert. Bogert goes to confront Lanning, and Calvin goes to talk to Ashe. Ashe, however, reveals that he is getting married to another woman. Calvin is devastated, and realizes that Herbie was lying to try not to hurt her feelings, and that he lied to Bogert as well. She tells Herbie to tell Bogert the truth, but Herbie is caught in a paradox in which lying will hurt Bogert’s feelings and telling the truth will hurt his feelings—both of which will violate the First Law. He collapses and remains silent.
In “Little Lost Robot,” Calvin and Bogert are brought to Hyper Base, where a robot named Nestor 10 has been lost. Because of the nature of Nestor 10’s work, it has been modified with a weakened First Law, so that the robot does not have to act if a human is going to come to har,. A worker named Gerald Black grows frustrated with Nestor 10 one day, and tells the robot to “go lose [himself].” And so Nestor 10 places himself in a room with 62 other identical robots. Calvin and Bogert try to devise a series of experiments that will reveal which robot is Nestor 10, but none of the trials are successful. However, when Calvin learns that Nestor 10 has advanced physics knowledge, she devises an experiment where he is caught in a trap of superior knowledge and thus reveals which robot he is—as Calvin notes, his superiority catches him.
In “Escape!” the officials at U.S. Robots and Mechanical men are trying to build a ship that can travel faster than the speed of light. They use instructions from another company called Consolidated and feed it to their robot called The Brain. As The Brain is figuring out how to build the ship, Calvin tells him that they don’t mind if humans are harmed or even if they die. This is because in the interstellar jump, the humans temporarily cease to exist—effectively dying for a moment. The Brain is taken aback, but understands. He instructs other robots on building the ship, and Donovan and Powell are brought in to test it. But when they are given a first tour, the ship takes off without their knowledge. They discover that they cannot fly the ship, that there are no showers, and that they only have milk and beans to survive off of. They experience the hyperspace jump, wherein they have strange visions of death. The Brain brings them back to Earth, and Calvin realizes their experiences were all her fault. The Brain was simply following her instructions, and as she puts it, he became a “practical joker” in order to cope with the fact that he would be killing the humans—if only temporarily.
In the next story, “Evidence,” two men are running for a mayoral office, Francis Quinn and Stephen Byerley. Quinn believes that Byerley is a robot, because he has never seen the man eat or sleep. He enlists Calvin and Bogert to prove that he is a robot. But Calvin points out that if Byerley follows the Three Laws, he could be a robot, or he could simply be a very good man. Quinn has several men investigate Byerley, but cannot come up with concrete evidence. He leaks the news, and the public is outraged. However, Byerley ultimately proves that he is a human by punching a man who threatens him at a campaign speech, violating the First Law, and Byerley wins the election. But later, Calvin visits him one more time, and reveals that he could have hit the man if the man was also a robot. She tells the reporter that she still believes Byerley to be a robot.
In her final story, “The Evitable Conflict,” Calvin works once again with Byerley, who has now become World Coordinator. The year is now 2052, and the global economy is being stabilized and run by robots called Machines. But Byerley observes that there are some unusual errors occurring, like over- and underproduction in certain economic regions. His advisors tell him that the Machines don’t make errors because they follow the First Law, and so he enlists Calvin’s help to figure out what is wrong. Gradually, Calvin realizes that all of the companies and people who have been hurt by the Machines’ errors are related to an organization called the Society for Humanity, which is very anti-Machine. The Machines recognize that their presence is extremely beneficial to humanity, and so they need to “take care of” any threats to their own existence. They are following the First Law and trying to create the most good, which means ensuring they maintain control of the economy.
Calvin concludes to the reporter that that’s all she can tell him: she witnessed the evolution of robots from the time they couldn’t speak to the time when they stand “between mankind and destruction.” She says goodbye, and eventually dies at 82 years old.
