An entertaining and thoughtful book about the end of the world as we know it and a robot who wanders through it and comes out at the end with, perhaps, a way to remake the world to be better. The story is full of SFF and literary allusions to writers and situations, especially Asimov's positronic robot stories, as well as other writers like Kafka, Orwell, Borges and Dante.
Charles is a robot valet and, as the story begin, murders his master. He suspects a malfunction and leaves the mansion to return to a central service for decommissioning. During the journey, we see the world through his eyes, and it is a world that has decayed and gone to waste, with no humans to be seen, but lots of robots, all waiting for confirming instructions from humans that never come.
His journey is in vain, for other robots are waiting before him to be examined. Now things take a turn for the unexpected when he meets up with an unusual 'robot' known as the Wonk, who adds unexpected tasks and trigger a re-interpretation of tasks in Uncharles' (formerly Charles) decision-making process.
The Wonk is attempting to find out what happened to the world. And together, they will make a journey through a wasteland landscape to find answers: first in an underground farm that is trying to recreate the mindless workplace of the past, then in a Library Archive that doesn't really archive, and so on. As the journey progresses, Uncharles begins to see loopholes and new ways to reinterpret his instructions, all the while trying to figure out his place in the now desolate world, which no longer needs his skills as a valet.
Their journey would end when they end up in the only place left with authority. But the answers they get there would not be the ones they expect, and the only way to survive is to challenge authority and come up with their own way to remake the world.
The story is full of social commentary about how we live and how robots are treated, if we had intelligent but not sentient robots. The question of robot sentience is asked many times in the story, but the answer may depend on how you interpret the ending of the story.