"Nation Iroquoise" presents an intriguing mystery. Found in the Bibliotheque Mazarine in Paris and in the National Archives of Canada in Ottawa, the unsigned and undated manuscript Nation Iroquoise is an absorbing and informative eyewitness account of the daily life and societal structure of the Oneida Iroquois in the 17th century. The "Nation Iroquoise" manuscript is arguably one of the earliest known comprehensive descriptions of an Iroquois group. Rich in ethnographic detail, the work is replete with valuable information about the traditional Oneidas: the role of women in tribal councils; mortuary customs; religious beliefs and rituals; warfare; the function of the clan system in tribal governance; the impact of alcohol; and the topography, flora, and fauna of the Oneida territory. It also offers important information about the famed Iroquois Confederacy during the 1600s. Drawing on multiple strands of evidence and following a trail of clues within the "Nation Iroquoise" manuscript and elsewhere, Jose Antonio Brandao presents the results of a fascinating and convincing piece of detective work. He explains who might have written the manuscript as well as its contribution to our understanding of the Iroquois and their culture.