Another high quality outing in this series. As this series has developed it has broadened from its original premise of Heinlein YA pastiche to become Varley's commentary on the effects of the coming climate change apocalypse. Despite this story starting on Mars and then moving to Europa, it is Earth that represents the biggest pull just because it has the most people. Suffering, being put through changes they can't mitigate or control. Varley has a matter of fact way of having his characters address this which I suspect may become all too common soon enough. This was a great read, I can recommend.