On 26 March 2020—exactly 425 years after the death of Simon of Trent—the Italian derivative "painter" Giovanni Gasparro published on Facebook a picture that he titled The Martyrdom of St Simon of Trento (Simon unverdorben) in accordance with Jewish ritual murder. This antisemitic fantasy nevertheless points to a historical trajectory in the history of Christianity that is at once significant and painful: the transformation of the deicide narrative across the centuries. As an almost existential theologoumenon within Christianity, the deicide motif proves, however, to be remarkably fluid over time: from its direct articulation in the context of its emergence—within the apologetic epoch of the history of theology from the second century onward, and in the Adversus Iudaeos texts of Late Antiquity—to medieval variations in the form of ritual-murder and host-desecration narratives, which, around the middle of the last millennium, culminated in dramatic anti-Jewish attacks, including the early modern fake news surrounding Simon of Trent. Yet many modern conspiracy narratives also exhibit a recalibration of these ritual-murder stories: without naming "THE JEW," accounts such as the Pizzagate story or the Q-Anon conspiracy narrative draw on precisely such images and narrative patterns. The lecture will offer a (theological-)historical contextualization of this theologoumenon, using as a case study the antisemitic visual rhetoric and the conferral of meaning and "signature" associated with Simon of Trent.