From the introduction: The twenties of the XX century. The Global Society of Inquisitive and Investigative embraces the curious from every corner of the world. Their paradigm is the knowability of the Universe. They believe in the triumph and omnipotence of science. And now, when the Great War is over, the Society faces the challenging task to distinguish hidden from fictitious basing on the centuries-long legends. The alarming news came a day ago: a huge city literally rose from the ocean abyss near the shore of Douarnenez (France). The exquisite high gate of the city had the name carved on it — Ys.