John Varley's Steel Beach is a daring, well-conceived work of science fiction. Humanity has been ejected from Earth by enigmatic aliens trying to save cetaceans. Homo sapiens finds itself exiled to strongholds throughout the solar system, foremost of which is Luna. There, human beings live in great comfort with almost all of their needs met and very little to worry about. As a result, they are losing their minds.
Through the unremarkable antagonist Hildy, Varley asks what happens to human beings who lack challenges and who lack any real direction. Comforts there are aplenty in Luna. Technology makes sex changes routine and has all but defeated death itself. So now what? Humanity has slumped into a self-absorbed torpor that would be bad enough if the unimaginably complex supercomputer that controls every aspect of Lunar life weren't on the edge of a catastrophic breakdown. Hildy gains an increasing awareness of this problem as the narrative progresses; and he (later she) manages to struggle out of the cocoon of smothering comfort that threatens to make humanity incapable of responding to the imminent central computer breakdown.
As with much good science fiction, Varley uses Steel Beach to ask what humanity ought to do with its capabilities. He suggests that it is human nature to use awesome abilities for small-minded diversions. We are our own greatest limitation, though we are also our own greatest resource.
The story is overlong, though. The pace drags a bit. More ruthless editing would have yielded a story that was better-paced but still covered the important points.
Though it can be uncomfortable to read (or perhaps because), Steel Beach is quite worthy of the reading.