In the early twentieth century, Margaret Murray proposed the theory that elves were the still-present but hidden descendants of the Neolithic occupants of Europe who were displaced by the arrival of the Celtic speaking Indo-Europeans. Known as the "Hidden People" because they fled before the invaders to live in secret enclaves in forests and caves, Murray proposed that the tales of these indigenous people gradually changed over time until they were transformed into magical creatures like the Celtic Tuatha de Danaan. But, what if the tales were true? What if these people were not modern Homo Sapiens, but a different race who actually had the abilities ascribed to them? And, what if they still exist?

The Imramma (a Celtic word for a spiritual journey or mystical voyage) of the Hidden People, the story of four of the descendants of these people, is a tale of romantic enchantments and magical journeys which explore the legend of the Grail, from its inception in ancient Gaelic myth to its development in the tales of King Artúr and the claims of the Merovingian connection to Jesus, Mary Magdalene and Joseph of Arimathea. Along the way, it reveals the different forms the Grail has taken, from the "stone that fell from heaven" in the works of Eschenbach to the bloodline of Christ proposed by many modern authors, and perhaps the real answer to the question, "Whom does the Grail serve?"

The three planned volumes of The Imramma take their titles from the phrases that indicated regions beyond the known world on ancient maps - Here There Be Dragons, X Marks the Spot and Point of No Return.