In this documentary, Karlheinz Mund investigates the fate of the missing painting The Tower of Blue Horses, created by expressionist artist Franz Marc in 1913. The work was a main attraction in the New Wing of the Berlin National Gallery from 1919-1937, before being removed from display by the Nazis as an example of so-called "degenerate art." The painting has been missing since 1945 and its whereabouts are unknown.

The documentary also presents the life of the artist and the 1937 Degenerate Art exhibition.