This book examines how the Covid-19 pandemic can be described as a biopolitical crisis, taking into account a fact often overlooked by commentators: Covid-19 is a zoonosis, a disease transmissible between animal species. The Sars-Cov2 virus causing this respiratory disease circulated in bats before passing to humans under as-yet mysterious conditions, and it was transmitted from humans to other species, notably mink and deer. Building on Michel Foucault’s revival of the term “biopolitics” and related notions (disciplinary power, pastoral power, cynegetic power), this book traces a set of public health measures taken over the last two centuries to control epidemics. It underlines how the need to conserve virus strains in order to identify and anticipate their mutations has given rise to cryopolitics, a set of techniques aimed at suspending the living in order to defer death. The book then questions the emancipatory scope of this cryopolitics by examining interspecies solidarity built by the warning signals sent by animals to humans about coming threats, be they pandemics, natural disasters, or climate change. By blurring the boundaries between the wild and the domestic resulting from the process of domestication, the politics of zoonoses relies on sentinels who preserve the memory of signs from the past to prepare living beings for future threats by involving them in a common ideal.