Solaria was the last of the Fifty Spacer Worlds to be settled. It had gained its independence not so very long ago. It was unique among the Spacer worlds. There was no other world quite like it. None of the Spacers lived as uniquely as the Solarians. Nexonians had been the first to settle Solaria. Nexon was becoming quite crowded. By Spacer standards, of course. Never by the standards of Earth! On the new world, Nexonians established huge estates, and many tended to stay on Solaria all year round. Fortunately, however, they began to realize how if not taken great caution, Solaria would soon be as crowded as Nexon had been. The Nexonians who had already established estates on Solaria immediately went on to establish their independence.

Upon settling Solaria, and living on huge estates, there was, of course, a need for robot labor, as there was on all Spacer worlds. However, as the estates were large, and there were few humans, the number of robots grew. Due to the large number of robots, many on Solaria took to designing newer models, and Solaria became known throughout the Spacer worlds for their robots.

Now, Solaria was a peaceful world. A perfect world. There was no danger of overpopulation, as the fetologists saw to it that births balanced out deaths. There was someone chosen every ten years. However, there was one exception. Rikaine Delmarre. He had volunteered for life! There was not a Solarian who wasn't shocked by this. To volunteer?! For such a horrid and dirty job!!! However, Delmarre did. He had also decided to train someone as his assistant and successor. Delmarre was a strict Traditionalist, and a man of advanced notions. He would speak of his work to other Solarians. And fetology wasn't all he was interested in, but in several other things, including robotics, of course.

There was no argument that the Solarians were the best roboticists in the galaxy. Not all Solarians were roboticists, of course, but Solaria was well-known throughout the Spacer worlds for its advanced robot exports. However, the best roboticist, was not a Solarian, but an Auroran.

Han Fastolfe had achieved to create a humaniform, Robot Daneel Olivaw. Daneel had been originally meant to help Fastolfe and Sarton bring about the settlement of the galaxy. However, since Sarton's death, Daneel had been assigned to the task of helping solve the murder with the help of Plainclothesman Elijah Baley, and Earthman. Afterward, Daneel returned to Aurora with Fastolfe and the rest of Spacetown.

Now Fastolfe would keep Daneel with him. After all, he was the first humaniform robot. And now that the settlement of the galaxy seemed almost certain, there was no need to send Daneel into the City to help bring it about. Daneel need have no function, of course, Fastolfe would simply keep him, as his greatest achievement. As of now, anyway.

How Plainclothesman Baley had solved the case, on Earth, become known on all the Spacer worlds. Including Solaria, of course. But very few noticed, or rather, very few cared. Everything changed when one night, the summoning signal flashed, and a robot arrived at 's laboratory to find dead, and his wife, Gladia Delmarre unconscious next to him.

Word would eventually reach the other worlds, of course. Including Aurora.