It has been sold to 100 countries, spawned international interest in the fashions of 1920s Berlin and, in 2020, Germany’s first TV blockbuster of the streaming era returns for its third season, promising more murder and mystery in the turbulent days of the Weimar era.

Based on the bestselling detective novels by Volker Kutscher, Babylon Berlin is the most expensive non-English language screen production ever. Its cast is a who’s who of Germany’s best actors, headed by Liv Lisa Fries, playing the impoverished stenographer and aspiring detective Charlotte Ritter, and Volker Bruch, who plays her superior, chief inspector Gereon Rath.

Both investigators harbour secrets, with Ritter turning to prostitution at night to subsidise her family, and Rath battling PTSD triggered by his experiences in the first world war as well as leading a complicated love life.

The backdrop is 1929 in Berlin, a city in turmoil as it undergoes profound cultural, economic and political change. Nazis lurk in the wings, ready to exploit the desperation caused by poverty and unemployment. The foundations of the young republic show signs of crumbling and, as if in expectation of its imminent demise, the city’s inhabitants, including the protagonists, indulge in a frenzy of dancing, drug-taking and cabaret parties.

From left, Meret Becker, Jenny Schily, Leonie Benesch, Hannah Herzsprung, Liv Lisa Fries and Fritzi Haberland at the premiere of the third season of Babylon Berlin in Berlin. Photograph: Hayoung Jeon/EPA

At its recent red carpet premiere in Berlin, and the after-party event in a dairy factory from the Weimar era, cast and audience members wore cloche hats, flapper dresses, spit curls and drag queen looks, underlining how the show has caught the public’s imagination.

A 1920s musical, guided tours of Weimar Berlin, including many of the locations in the show, a rise in popularity of burlesque nightclubs and table telephone bars, as well as a flurry of books and music, are among the cultural spin-offs.

Liv Lisa Fries plays the aspiring detective Charlotte Ritter. Photograph: X Filme

Liv Lisa Fries, wearing a 1920s-style cinnamon taffeta gown at the premiere, has also become caught up in the craze. “It’s fascinating. I know a lot of people wanting to have their hair cut in a bob like Charlotte, who are wearing her cloche hat. They also like the real world of this film, and how my character boxes her way through this very male world to fulfil her goals.”

Its creators, the director-screenwriter trio Tom Tykwer, Achim von Borries, and Henk Handloegten said they sometimes had difficulty keeping up with reality, citing economic and political upheaval around the world. “I’m reluctant to say it, but similar things are happening in the world today,” said Tykwer. “It has also been one of the big challenges. We have had to keep reminding ourselves to stick to the point of view of the characters in 1929, otherwise it will become cheap.”

The production team on the set of Babylon Berlin. Photograph: X Filme

It has surprised some in the entertainment industry that Germany was so late in entering the field of television blockbuster serials, which has been dominated by the US, Scandinavia and the UK.

On the eve of the launch of the third season of Babylon Berlin, and with a fourth season in the pipeline, Germany is now considered to be firmly established in the genre.

A remake of Germany’s hitherto most successful TV export, Das Boot, came out in 2018 to critical acclaim. Other series, such as Der Pass (Pagan Peak) and Acht Tage (8 Days) are also making an international impact. Deutschland 83, a drama based on recent German history, is particularly popular in the US and is also about to launch its third season. The sci-fi eco thriller Der Schwarm (The Swarm), based on a popular novel by Franz Schätzing, is creating a buzz even before shooting starts next year.

A scene from Babylon Berlin, season three. Photograph: X Filme

But critics in Germany have taken umbrage at the extent to which the compulsory TV licence fee, one of the highest in the world, has provided the bulk of the €40m (£34m) funding for Babylon Berlin, which is co-financed and produced with Sky, whose subscribers will see it in January. German terrestrial television will not broadcast season three until the autumn.

Tykwer, also known for Run Lola Run and Perfume, defended the model. “Many more people – something like 10 times as many – watched the first two seasons on the public television station ARD,” he said. “The year before it was shown on ARD, it didn’t really exist for most German viewers, most of whom, I have to say, are still watching linear television.”

Season three was kept under wraps until its premiere in December but the Guardian was allowed on to the Studio Babelsberg set. In reconstructed 1920s Berlin streets, with a pawn shop, a millinery, restaurants and brothels, fog, rain, the hoot of car horns and the stink of exhaust fumes, Tykwer was overseeing a key scene from the end of episode two.

Volker Ruth plays Chief Inspector Gereon Rath. Photograph: X Filme

We watched as Chief Inspector Gereon Rath, holding on to his trilby, dashed down the stairs of a tenement block, elbowing everyone out of his way, including a cartload of chickens. He caught the witness to the murder of a silent screen actress, bundled him into a car for the briefest of interrogations, before the man was immediately shot dead. Rath was left bewildered and sprayed in blood.

“It’s joyful to shoot, even if it’s physically draining,” said Tykwer when the scene was finished. “We shoot these 12 episodes in 100-120 days, whereas you would usually have 40 for cinema or 20 for a TV show. The dedication you need for something so long term is quite absurd.”

After wiping the sweat from his brow, Bruch said he had learned a lot about the period while playing Rath. “At school it was so squeezed between world war one and two,” he said. “So it was useful to have lots of historical experts to prepare us, everything from the police work to the politics, the psychology and the nightlife. They even taught us how to dance the Charleston.

“My character is haunted by the past and that describes the era well because it was at this time, with German resentment over paying war reparations, and the suffering of living standards, that created political turbulence, which all leads to a horrific future we know too well.”