Nachtland - black comedy by Marius von Mayenburg

Nicola and Philipp's father has died. While clearing out the house, the siblings find a watercolor, small, simply framed, a village idyll with a church, not really worth mentioning if it weren't for this signature: "A. Hiller." Or is the first "l" a "t"? An expert confirms the suspicion that a dealer is making an indecent offer. Does the painting have artistic or financial value and is it morally justifiable to make money out of it?
The exchange of opinions between the parties becomes increasingly bizarre, not least because of the Jewish daughter-in-law and the grandmother who is described as a Nazi.

A black comedy about the question: can art be viewed independently of its creator? Where are the boundaries?