‘Babylon Berlin’ Is Back. Here’s What You Need to Know.

Over the years, the lavish German noir detective series “Babylon Berlin” has required patience from its American viewers.

First, fans had to untangle dense story lines — set across the late 1920s and early 1930s — along with an abundance of compulsively watchable characters, most of them harboring secrets. Then they had to wait years for new episodes. Netflix initially carried the first three seasons, but they were removed from the platform this year. Season 4 aired in Germany and elsewhere in Europe in 2022, but these newer episodes have only now become available to stream in the United States, arriving on MHz Choice, a platform specializing in European titles, on Tuesday.

This fourth season is “more music, more crime, more sex, more politics than ever before,” said Henk Handloegten, who created “Babylon Berlin” along with Achim von Borries and Tom Tykwer. It also features more Nazis.

Season 4 opens on New Year’s Eve 1930, and German politics is kicking into a higher, scarier gear. “Suddenly, our heroes are confronted with a completely new and profoundly disturbing and menacing energy: the rise of fascism and the far-right,” Tykwer said in a joint video interview with his two colleagues.

Based on a series of books by Volker Kutscher, “Babylon Berlin” sets fictional characters against a backdrop of real events, so we know that Hitler’s rise to power will end the democratic Weimar Republic. The season’s suspense lies in discovering “how these characters we’re getting to know are reacting to the upcoming Nazi period,” von Borries said. “Will they be on the right side or the wrong side?”