In this introduction, the author presents the conditions of her fieldwork, conducted inside the prison where her husband was waiting for a judgment. She explores the gains and consequences of her insider-outsider status as a visitor and the way she transformed her involvement into a calibrated instrument of knowledge production. This chapter presents the ethnographical questions that became the central issues of the book, as well as the theoretical problems that carry. The central question is the presence of the First Command of Capital (Primeiro Comando da Capital – PCC) even where it is absent, or, in other words, even where it does not encounter any of its members. This matter is put in dialogue with some criticism concerning the concepts of society, culture, group and individual made by anthropology, philosophy, Melanesian and Amerindian studies, as well as the limits of this criticism.