'The Hidden Church of the Holy Graal' by Arthur Edward Waite is a mystical and esoteric exploration of the legendary Holy Grail. Arthur Edward Waite, a renowned occultist and scholar, delves into the symbolism, mythology, and spiritual significance surrounding the Holy Grail. In the book, Waite presents a detailed examination of the Grail legend, drawing from various sources such as Arthurian legends, medieval romances, and Christian mythology. He explores the historical and symbolic origins of the Holy Grail, its connection to the life of Jesus Christ, and its role in the mystical traditions of Christianity.