To be an absolute monarch, as was the 17th-century French king Louis XIV, entails the ability and unquestioned right to imprison anyone at any time without cause, explanation, or reason. Such was the case for Eustache Danger and others who in one way or another displeased the crown. Held in secrecy for 34 years with strict orders from Versailles to never speak his name, Danger became known simply as the “ancien prisonnier.” Around this mysterious prisoner, a legend emerged of an unidentified man encased in a mask, which was later popularized in fiction and film. Based on extant primary sources and recent scholarship, as well as theories, rumors, and conjecture, this book by British biographer Wilkinson (Louis XIV: The Power and the Glory) interweaves the stories of Danger, his jailor, other prisoners held at the same time, and the four prisons where Danger was held (ending with the most famous of all, the Bastille). It is a telling narrative of the excesses and pettiness of an unchecked aristocracy and its privilege. The inclusion of archival photographs, letters, and maps help to offer a better understanding of the era. VERDICT Dense with detail, this comprehensive work requires some knowledge or interest in this specific period of French history.