Thomas Sheridan's 2016 book, the The Druid Code: Magic, Megaliths and Mythology, was a result of his personal quest to 'get inside' the minds of the Neolithic and Bronze Age megalithic builders by using the comparative mythologies across the entire European Megalithic Arc between Norway and the eastern Mediterranean. A quest which unlocked a story of a profound shift in human consciousness, beginning around 2500BC, when an unknown disaster caused a possible tsunami which devastated Ireland, Brittany and Orkney in particular, and the resulting trauma of this event gave rise to the mythology of these regions. Mythologies and folklore which were to act as a kind of safety valve for the consciousness up until the arrival of Christianity in Britain and Ireland.
Then, something truly remarkable happened: the druids of Ireland infiltrated the early Christian church in order to use the same mythological stewardship to save Irish mythology within the early Irish church, and with it, the incredible wealth of information it contained; not just about ancient Ireland, but all of megalithic Western Europe. The druids had done their work and performed one of the greatest coups in history.
Thomas Sheridan also proposes that Ireland's famous Round Towers and 'Celtic' High Crosses are pre-Christian in origin, and were built before Saint Patrick arrived in Ireland, using engineering techniques that the Romans would later adopt and claim as their own. The Biblical-inspired East-to-West migration is a fallacy; and early Europe was, in actuality, a product of a West-to-East development, which began when a race of 'magicians' known as the Tuatha De Dannan arrived in Ireland from their four destroyed cities beyond the waves. Arriving from a sunken location which, in time, became known as Hy Brasil to many, and 'Atlantis' to Plato.