On the 60th birthday of his father Karl, who reunites the family for Shabbat, Simon wants to introduce his new girlfriend to her parents. But as always, they are busy with their own business. As if Simon were his best friend, Karl tells his son that he feels like he's thirty years younger since sleeping with Sonja, the new secretary. Simon allows his mother Agnes to force his hand to transcribe his father's book so that Karl does not go on vacation with Sonja. While his parents sunbathe on a nudist beach, Simon enters a spellbinding cat-and-mouse game with Sonja and finds himself more and more stuck in the inextricable web of family relationships.