The film is set in present-day Berlin. The heroine Undine is a consultant for the city development bureau. Her current boyfriend suddenly breaks up with her, and an ancient curse seems to be fulfilled. In medieval legends, Undine is a water spirit. If the man they are with betrays them, they will kill the man and return to the water. The heroine of the film wants to resist this curse, so she leaves Berlin. At this time, she meets Christopher, an industrial diver working in a reservoir area in western Germany. The two fall in love. Soon after, Christopher realizes that Undine seems to be running away from something and feels betrayed... "Undine" is the first part of the "Elemental Spirit Trilogy" planned by director Petzold. The next two parts will involve the air elf Sylph and the earth elf Gnom.