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... It really does help if you have some familiarity with the story of the eponymous water nymph - otherwise much of this will seem disjointed. The use of the sunken boat in the lake, and strong efforts from Beer and Rogowski give this a depth to it; the characterisations develop slowly but definitely. True, Christian Petzold does take his time, and what is effectively quite a short story can seem a little overly padded now and again, but the imagery under the water and the subtly of the story are well carried by all. It made better sense to me second time round, and is well worth 90 minutes. If you do enjoy it, try the 1916 version - that is shorter and just as beautiful to watch.