The series is about four families in a German small town across three generations. Some of the characters have become aware of a time portal in a cave near a nuclear power station which opens every 33 years, creating all sorts of time travel paradoxes when some of the characters start to travel back and forth in time. Some stumble into it by mistake, others are lured there with dire consequences and some are using it to their advantage. The series starts in 2019 with a suicide and the disappearance of a young boy
The characters are played by different actors at different stages of their lives and they are mostly very well cast, though at times it does get tough keeping up with who is who across the decades. Some of the older cast members were stars of the German New Wave like Angela Winkler (Katharina Blum, The Tin Drum) whose distinctive facial mole makes her the easiest to keep track off over generations. Lisa Kreuzer starred in several of the early Wim Wenders films.
When it comes to genres like horror and sci-fi and German film and TV hasn't produced much of note since the 1920s but this can compare itself with the better recent genre shows out there. It looks great and has one of the best scores for a TV show I can remember. Ends on a great cliff hanger too, which has me intrigued about season 2.