Embodying the dismissal of Vatican II, the 1962 self-published libel IL COMPLOTTO CONTRO LA CHIESA, which mixed anti-Judaism, modern antisemitism with Catholic traditionalism, became by 1965 a world best-seller. It has since fueled a counter-memory and counter-legacy of Vatican II. Its authors built upon conspiracy theories to legitimize and make sense out of their own, now minoritized position. In return, their counter-Revolution ideals shaped their own practices, activism and organizations. For Vatican II historians, cross-referencing Church materials with police sources offers new angles to analyze conspiracy theories in the aula. THE PLOT's scandal set a multi-level collaboration to tackle antisemitism: European intelligence services, Jewish defense agencies and Israeli State security looked for the author(s) behind the penname Pinay. Five decades after the Protocols, it unearths the dynamics of a lesser-studied global far-right Catholicism, between Europe, the Americas and the Middle-East. Investigating THE PLOT's writing, printing and distribution networks, we outline the dynamics of fear and rumors, Holocaust memory, and the shift of alliances, as neo-fascists took a pro-Arab stance in the decolonial era. Far from a "new antisemite international" fueled by ex-Nazis on the run, from Argentina or Brazil to Egypt - as Israeli services feared, THE PLOT was written by lay groups, whose understanding of a conspiracy against the Church was shaped by the Catholic traumatic memory of the Mexican Revolution. Coming to Rome to use the council as a platform, they found logistical support in the neofascist Centro Studi Ordine Nuovo, securing through the latter financial help from the Egyptian Ministry for Tourism, as part of Nasser's diplomacy at Vatican II. Far from a group of lunatics promoting fringe antisemitism, this dissenting and marginalized minority was supported by organized groups. Bea's files indeed hint at 2 names in top Church circles: Ottaviani and Balaguer