As the title suggests, this new book from Kate Kelly is a kind of mirror-image counterpart to her earlier novel, The Arid Lands , from 2023. You can find my review of that one on Goodreads. Both feature futures where, owing to changes in the global climate, human society has become much more fragmented, with some communities retaining a higher degree of civilisation than others. In the first book, set in a hot, dry future, the range was roughly from the 1950s back to mediaeval times. In this one, set in a much bleaker, deep-frozen future, the mediaeval culture is actually the more modern one, beset on all sides by barbarian savagery. The plots of the two books have a mirror-image quality, too. The first one is about a late-teen female protagonist whose initial concern is simply to look after her slightly younger male sibling, but then ends up having to save the world virtually single-handed. Permafrost has a similar scenario, but with the genders reversed. As far as the actual stories...