In a dystopian future where the Earth is almost completely covered in water due to the melting of the poles, a lonely wanderer named Mariner, played by a new actor, is an expert navigator fighting for his survival in a world without land. When he meets Helen, a mother desperate to find a legend of the mainland, they embark together on an adventure across the vast ocean filled with danger and decaying societies. On their journey, they discover deep secrets about Earth's past and the destiny of humanity.
