The American criminal justice system was in flux in 2020, a clash of possibilities for reform, retrenchment, and radical change—nowhere more so than in Massachusetts, which had just passed major criminal justice reform. The COVID-19 pandemic interrupted the moment with life-threatening force, ravaging people held in prisons and jails across the country. However, it did not so much create new deprivations and suffering as it exposed prisons as sites of physical, institutional, and psychological violence that do not make communities safer. At the same time, advocates for people in prisons—including many incarcerated and formerly incarcerated people—seized on the pandemic’s disruptions to demand change. Detailing the first year of the pandemic inside the Massachusetts state prison system, this book argues that the history of the pandemic inside prisons exposed both the cruelties of incarceration and the power of change when it is led by directly affected people.