For a Breath I Tarry was written in 1966 by Roger Zelazny. It takes place long after the end of humanity and mainly explores the conflict between man and machine.
Man created robotic assistants before humanity died out and entrusted them to build everything around them. Even after mankind ended, the robots continued working. Solcom worked in the sky and Divcom worked underground. However, Divcom could only be activated if Solcom somehow stopped functioning.
Humanity was annihilated by an atomic missile, a missile that damaged Solcom when it struck. Divcom began to work after Solcom was compromised. However, Solcom was able to repair itself, and neither robot would work together or accept the other's position in the world.
Solcom and Divcom had two agents, also machines: Frost and Beta. Frost was in control of the northern hemisphere, Beta of the southern. Interestingly, Beta seems to possess a female personality even though she is a robot. Frost was very curious about Man and set off on a search for anything that was left of human civilization, as he had never seen humans before. One day, he stumbles upon Mordel, a servant of Divcom. He showed Frost books written by humans and shared what he knew about the lost humankind.
Frost and Mordel then make a deal, which Divcom later becomes involved in. Frost will attempt to become Man, but if he couldn't, he would serve Divcom forever. Frost embarks on a thousand year quest to become a human, and he eventually succeeds through recovered human DNA. Once he becomes Man, he invites Beta to join him. Beta agrees, and the story ends with the implication that Man will be reborn.