Climate scientists point to permafrost as a “ticking time bomb” for the planet, and from the Arctic, apocalyptic narratives proliferate on the devastating effects permafrost thaw poses to human survival. In , Charlotte Wrigley considers how permafrost—and its disappearance—redefines extinction to be a lack of continuity, both material and social, and something that affects not only life on earth but nonlife, too. approaches the topic of thawing permafrost and the wild new economies and mitigation strategies forming in the far north through a study of the Sakha Republic, Russia’s largest region, and its capital city Yakutsk, which is the coldest city in the world and built on permafrost. Wrigley examines people who are creating commerce out of thawing permafrost, including scientists wishing to recreate the prehistoric “Mammoth steppe” ecosystem by eventually rewilding resurrected woolly mammoths, Indigenous people who forage the tundra for exposed mammoth bodies to sell their tusks, and government officials hoping to keep their city standing as the ground collapses under it. Warming begets thawing begets economic activity— and as a result, permafrost becomes discontinuous, both as land and as a social category, in ways that have implications for the entire planet. Discontinuity, Wrigley shows, eventually evolves into extinction. Offering a new way of defining extinction through the concept of “discontinuity,” presents a meditative and story-focused engagement with permafrost as more than just frozen ground.