Russian geophysicist Sergey Zimov and his son Nikita are gathering any large woolly beast they can get their hands on and transporting them, by whatever low budget means they can contrive, to the most remote corner of Siberia. They call their project Pleistocene Park. Their goal: restore the Ice Age “mammoth steppe” ecosystem, thereby preventing Arctic permafrost melt, slowing its release of sequestered carbon, and avoiding a catastrophic feedback loop leading to runaway global warming. Can two Russian scientists stave off a worst case scenario of global environmental catastrophe and reshape humanity’s relationship with the natural world? The clock is ticking.