Until Proven Safe is a pleasurable account of two authors as “quarantine tourists”. This is a term the authors actually use to describe John Howard, an eighteenth-century British prison reform advocate who travelled the breadth of England, Europe (including Russia), up to the city of Constantinople (present day Istanbul) and Greece, visiting prisons (pgs 41-79). The somewhat eccentric millionaire Howard made this journey to study best practices of imprisonment in his time in order to advocate reforms in British prisons. During his travels, he noticed that several European nations maintained a network of lazarettos (initially designed as institutions to hold leprosy patients in the fourteenth century) to isolate traders from North Africa and the Middle East who were seen as carriers of disease to Europe. Howard’s severely critical account of quarantine practices remains, on the account of our authors, legendary to this day.