Our planet has been many different worlds over its 4.5-billion-year history. Imagining what they were like is hard—with our limited lifespan, deep time eludes us by its very nature. Otherlands, the debut of Scottish palaeontologist Thomas Halliday, presents you with a series of past worlds. Though this is a non-fiction book thoroughly grounded in fact, it is the quality of the narrative that stands out. Beyond imaginative metaphors to describe extinct lifeforms, some of his reflections on deep time, taxonomy, and evolution are simply spine-tingling.