Confronting organized crime requires an understanding of its workings. The Zeta Yoke is based on legal documents made available by the government of the state of Coahuila, information submited by the National Human Rights Commission and an exhaustive research of other material. This report details how the Zetas controlled northern Coahuila for several years and their interactions with the authorities at various levels. It focuses on this cartel's control of the Piedras Negrasprision and the brutal reprisals in Allende and other local districts following a betrayal, responsibility for which lies at the door of the DEA and Mexico's Federal Police.