The story takes place is some distant future, but definitely on Earth. The protagonist is a young man named John, who is one of the Hill People. As he learns to be a priest, he has a vision of the Dead Place.
He bade me look into the smoke of the fire and see—I saw and told what I saw. It was what I have always seen—a river, and, beyond it, a great Dead Place and in it the gods walking. I have always thought about that. His eyes were stern when I told him he was no longer my father but a priest. He said, "This is a strong dream."
In order to become a priest, John has to go on a quest to see what he saw in his dream. His father fears it will destroy him, but the boy cannot become a priest until he goes and comes back.
John leaves for his quest, and travels far. He does find the City of the Gods after a perilous journey. There, he finds a dead god sitting by a window, and realizes it is just a dead man. He gets a vision from the god that his people need to return to the city, New York, and be renewed. John returns a priest, and leads the way.