In The Hidden Church of the Holy Graal, Arthur Edward Waite reads the medieval Grail corpus as veiled sacramental theology and a mystery of interior knighthood. Ranging across the Queste del Saint Graal, the Conte du Graal, and Joseph of Arimathea legends, he argues that the Grail signifies a Eucharistic theophany and the outline of an unhoused yet real Church. The study fuses antiquarian erudition with symbolist hermeneutics, offering annotations, source-collations, and fin-de-siècle prose poised between philology and mystical exegesis. Waite-British mystic, historian of esotericism, and co-creator of the Rider-Waite-Smith Tarot-brought to this project long initiatory and archival experience. A member of the Golden Dawn and a close reader of Cistercian spirituality, Rosicrucian manifestos, and Masonic rites, he resists folkloric or Celtic fertility explanations. His Catholic-leaning sacramental imagination, joined to dissatisfaction with reductive scholarship, led him to retrieve the Grail as a Christian theosophy encoded in romance. Readers of medieval literature, theology, and Western esotericism will find the work demanding yet clarifying. With patience, it yields a coherent map of symbols uniting romance, liturgy, and contemplative practice. It remains a bracing counterpoint to secularized Grail theories and a touchstone for spiritual-historical inquiry. Quickie Classics summarizes timeless works with precision, preserving the author's voice and keeping the prose clear, fast, and readable-distilled, never diluted. Enriched Edition extras: Introduction · Synopsis · Historical Context · Brief Analysis · 4 Reflection Q&As · Editorial Footnotes.