Paula Beer is "Undine", holding down a rather mundane job lecturing on the historical urban development of Berlin. She is also suffering the final throes of her relationship with "Johannes" (Jacob Matschenz) whom she still loves. As with the original Paracelcus myth (upon which this is based), she must avenge herself on anyone who betrays her - and we gradually begin to understand that there is much more to her than meets the eye. An heavy rain shower is instrumental in introducing her to "Christoph" (Franz Rogowski) and she finds another love but when she disappears into a lake, he must search...