The eldest of her daughters, Brunehilde, a five-year-old goldfish with a human face, takes advantage of her father’s moment of inattention to slip through a window of the submarine and reach the surface, under the parasol protector of a jellyfish. Fujimoto, a wizard who abandoned the human world to live on the ocean floor, experiments with “water of life,” a liquid that strengthens marine life He thus hopes one day to upset the ecological balance and see the sea, mistreated by men, regain its preeminence.