In this provocative and meticulously documented monograph, Reginald Freeman-former Executive Director of the Friary / Ordo Sacrae Flammae-offers a bold exposé of the hidden doctrinal architecture underpinning the Apostolic Johannite Church (AJC). Drawing upon firsthand experience, archival evidence, and comparative analysis, Freeman contends that the inner teachings of the AJC and its initiatic counterpart, the Friary, are deeply rooted in Setian and left-hand path philosophy, despite public denials by its leadership. The work begins with a personal preamble, addressing recent controversies and affirming the author's commitment to transparency and accountability. From there, Freeman systematically dismantles official narratives, juxtaposing AJC statements with organizational documents and initiatic teachings that mirror those of the Temple of Set. Through side-by-side comparisons of by-laws, ritual structures, and philosophical texts, the book reveals a striking continuity between the AJC's inner order and Setian metaphysics. At the heart of the analysis lies the doctrine of the Magister Templi IV°, a grade whose teachings-according to Freeman-are nearly verbatim to those found in the Temple of Set's Sapphire Tablet. The author explores the implications of this doctrine, contrasting its emphasis on apotheosis and radical individuation with the Christian Gnostic pursuit of theosis and reintegration. An appendix titled "Theosis Through Gnosis" offers a rich theological counterpoint, articulating the mystical path of divinization as understood within Eastern Orthodoxy and traditional Gnostic currents. Satan's Secret Pylon is not a polemic against Setian philosophy, but a call for doctrinal honesty and spiritual integrity. It challenges readers-especially those within the AJC-to examine the foundations of their faith and the egregores they empower. Whether embraced as revelation or rejected as heresy, this work is destined to provoke reflection, dialogue, and perhaps even reform.