Berlin during the ‘Golden Twenties’ was regarded as the most modern metropolis in Europe. People flocked to nightclubs to enjoy raucous, uninhibited and decadent parties. Berlin might have struggled to adapt to the fledgling democracy of the Weimar Republic, but it had less difficulty enjoying the freedoms it brought. In the 1920s, Berlin was regarded as the most modern metropolis in Europe. Life was described as a "dance on a volcano." People flocked to nightclubs to enjoy raucous, uninhibited and decadent parties. But the capital was also rife with poverty, misery and violence. Crime was epidemic. The Sass brothers, two bank robbers, became urban legends, and the specter of serial killers haunted the city. Ernst Gennat, head of the criminal police, was a gifted criminologist with an exceptional solve rate. He revolutionized forensic investigation practices and laid the foundations for modern profiling. The two-part documentary uses criminal cases to paint a picture of Berlin during the Weimar Republic, reconstructing events with the help of documentary photographs from 1918 to 1933, interviews with experts and case files. Hundreds of thousands of people in German cities like Stuttgart and Cologne face the prospect of being unable to drive to work because of bans on most types of diesel cars in downtown areas. Environmental Action Germany says diesel emissions cause the premature deaths of 13.000 people each year in Germany. Yet the case is not as clear-cut as it might seem. Environmental Action Germany (DUH) is behind the wave of diesel driving bans facing German cities. The NGO has taken authorities here to court for exceeding legal levels of nitrogen dioxide emissions. These are much lower in the European Union than they are in the United States, for example. While 100 micrograms of NO2 per cubic meter are permitted in the US, EU rules stipulate that levels should not exceed 40 micrograms. But the relation between road traffic levels and emission levels is not straightforward. Recently, Oldenburg recorded record levels of nitrogen dioxide pollution on a day when the northern city’s downtown was closed to cars and trucks. Experts are also at loggerheads. While environmentalists cite World Health Organization studies, lung specialists like Stuttgart-based hospital consultant Dr. Martin Hetzel have called the diesel debate “pure panic-mongering”. The former head of the German Respiratory Society (DGP), Dr. Dieter Köhler, agrees. He says cigarette smoke and smoke from candles are much more harmful. And the case of Hamburg also shows that driving bans are no quick fix. Two months after the introduction of the diesel ban, NO2 levels in the northern German city had increased rather than dropped. Twelve million German drivers of diesel vehicles are feeling the pinch. The cars being advertised as green just a few years ago are now worth practically nothing.