Imagine walking back in time through 500 million years. What would you see, smell, hear and feel in the worlds before ours? Palaeontologists Halliday and Brusatte, in conversation with science journalist Vince, take us through the story of life on earth, weaving together history and science. Halliday’s Otherlands: A World in the Making shows us the ecologies that survived and those that didn’t make it, and offers a new appreciation of the world that we are making now. Brusatte’s The Rise and Reign of the Mammals: A New History, from the Shadow of the Dinosaurs to Us looks at our mammal forebears and tells the stories of scientists whose fieldwork and discoveries underlie our knowledge.