Once upon a time gifted scientist Salvador saved the life of a young boy by transplanting onto him the gills of a shark. From that day the Ichtiander (that was the name the scientist gave to his adopted son) could stay underwater for days and dive to any depths, but being ashore became hard to him. Years later a quiet seaside town was hit with a wave of rumors about a strange creature that intimidated local fishermen. They called it the Sea Devil. In the meanwhile, a young man appears in the town. He doesn't associate with other people and is a perfect swimmer. He meets the daughter of a poor pearl diver called Goutierre and falls madly in love with her.