Paula Beer portrays Undine, working a rather ordinary job giving talks about Berlin’s urban history. She's also going through a difficult end to her relationship with Johannes (Jacob Matschenz), someone she still cares for. Like the Paracelcus myth that inspired it, there's an expectation of retribution against anyone who wrongs her – and we come to realize there’s far more to her than initially appears. A heavy rainstorm leads to an encounter with Christoph (Franz Rogowski), and a new romance blossoms, but when she vanishes into a lake, he feels compelled to look for her. Knowing the legend of the water nymph Undine is beneficial; otherwise, parts of the narrative might feel disconnected. The submerged boat in the lake, along with strong performances from Beer and Rogowski, contribute to the film’s richness; the characters unfold gradually but noticeably. It's true that Christian Petzold doesn't rush things, and what feels like a relatively brief tale occasionally seems stretched out, but the underwater visuals and the story’s understated nature are effectively conveyed by everyone involved. I understood it better on my second viewing, and it's deserving of 90 minutes. If you appreciate this film, consider watching the version from 1916 – it’s shorter and just as lovely to watch.

Source on TMDB