鋼鉄都市
Some details of Baley's life lack continuity throughout the Robot novels. In "The Caves of Steel", for example, it is noted that Baley's mother died shortly after his father was declassified (lost his civil classification and therefore all social and economic status), and that Baley did not remember her. However, in "The Robots of Dawn", Baley recalls his mother cajoling him to eat her chicken soup and telling him that even the Spacers did not have anything as good. In "The Caves of Steel", Baley is also reported to have a sister, but she is never referred to again. In the same way, Baley's intense shame at his father's declassification and the resulting deprivations of his childhood are not referred to in succeeding novels.