Adapted by Fassbinder from Alfred Döblin's classic 1929 novel of the underclass in Berlin during the Weimar Republic, this is not merely Fassbinder's longest and most ambitious film: it represents the crowning of the director's lifelong obsession with Döblin's novel and is considered by many to be his greatest film. Fassbinder identified closely with his protagonist, released murderer Franz Biberkopf, and of central importance to the plot is Biberkopf's intense friendship with another man. In fact, many of Fassbinder's familiar preoccupations are explored in depth: the destructive pressures of society and the inevitability with which people exploit and hurt those they love.