Original: The 1993 novel Die Entdeckung der Currywurst ("The Discovery of the Currywurst") by Uwe Timm was made into a 2008 film of the same name. The plot is based on an alternative but unproven theory that currywurst was invented in Hamburg.
Simplified: Although Berlin claims currywurst as its invention and "national dish", all over Germany, there are more than 20 different types of currywurst.