Museum objects not only convey history, they also have their own. However, their history often remains hidden. It is the job of provenance research to investigate these histories. It documents the many stages of an object’s journey on its way from the artist’s studio to the museum. The painting "Borussia" by Adolph Menzel provides a prime example of the almost seamless biography of an object. What are the clues present on the artwork itself which provenance research can follow up on? What does the back of a painting reveal and what part of its history does it disclose? What are the potential consequences of the findings of provenance research? The curatorial intervention provides us with a look behind the scenes of provenance research. In view of the ongoing debate about how to deal with the Nazi-looted art, it shows at the same time the change in the judicial and moral viewpoints from 1945 to the "Washington Conference Principles" in 1998.