The inventive and solidly enjoyable fourth novel set in the bubble world of Virga (after 2008's Queen of Candesce
) takes place far from the artificial suns that light the central regions. As entire towns fall victim to a mysterious threat, perhaps from “outside,” a religious movement begins insisting that the world is eternal, not created. The Eternists confiscate books, censor the news and force through a referendum subjecting science to popular vote, while sun lighter Hayden Griffin, familiar from previous books, teams up with local historian Leal to investigate the attacks. They find an expedition killed by rain, meet up with groups officially deemed “mythical” and fend off political threats and outside forces that aren't what they seem. Schroeder paints his unique world with deft touches while keeping the story moving briskly. (Aug.)