In 1787, the administrator of the hacienda El Puente, located in Xochitepec, by mandate of the territory's priest, imprisoned José Rojas in the ecclesiastical court.Allegedly, he was the author of "a paper which contains different heretical blasphemies and express invocations of the demon", written with blood.It began then an inquisitorial process that did not end until 1807.This article is an interpretive proposal of the speech embodied in that "heretical" paper.The analysis draws on the interdisciplinary perspective of studies on written culture, particularly on the hermeneutic perspective proposed by Iser and Foucault.