Ida wants to perform with her class at the annual Forest Day to campaign for the protection of the local forest. Even Helene is there, as she hopes to use the footage of the performance to build up her influencer channel. What nobody knows is that Helene's family is on the verge of bankruptcy and Helene urgently needs followers to avert the threat of bankruptcy. Helene is also under pressure from the high expectations of her magical animal, Karajan the cat from Paris, who imagines a life of pure luxury.
Retirees Karin, Gerhard and Philippa are not in the mood for Nordic walking and seniors' courses at the university. When Philippa, who is living life to the full as Leonie's godmother, helps the two to unexpected grandparenthood, they suddenly have two "lively" god-grandchildren to look after, a huge bouncy castle standing in the garden and Lego bricks stuck to their feet.
The ambitious punk rocker Max and the eco-activist Inge cannot stand each other, ever since Max publicly exposed her by singing the offensive song "When Inge is Dancing" in front of the whole school. But for Max and his classmates Fabio, Joscha and Lukas this song in particular has become a real hit at school as well as in the regional music scene: Their band called Systemfehler is on the verge of a breakthrough. But just before the important gig, which could get them a record deal, guitarist Josha is injured and can't play. Inge happens to be an excellent guitarist, and the only person who can fill in at such short notice. But when Max asks for her help, she imposes one non-negotiable condition: If she decides to play with the band, they will not perform the song "Wenn Inge tanzt".
The nine-year-old Nikolas has been missing for days. The criminal psychologist Claudia Meinert notices contradictions in her conversation with the parents of the missing child. In particular Nikolas' mother appears to be hiding something. When a video of the missing Nikolas surfaces, showing him tied up in a cellar, the trail leads to his school. The 13-year-old Leon and Mathilda strike the psychologist as conspicuous and provocative. Shortly afterwards, Meinert encounters the children with Nikolas' parents at the local swimming pool and her suspicions are confirmed: the parents are entangled in an insidious father-mother-child game with the possible suspects Leon and Mathilda. Now it is up to the psychologist to resolve the dark mystery of Nikolas' disappearance and save the child.
Nuclear security expert Katja Wernecke (Ulrike Folkerts) helps cover up a fire in the German nuclear reactor she works in, before the government takes a decision on extending the usage license for it. But the press uncovers it. PR man Steffen Stratmann (Matthias Koerbelin) is brought in to improve the companies image - but before he can implement his plan a nuclear meltdown occurs. 2m people have to be evacuated. Wernecke re-enters the hot zone to investigate the cause...
At the beginning of the weekend, the detective commissioner Tina Campenhausen wanted to spend with her family, she is called to a hotel in Travemünde. Guest Brederstein lies dead in the tub. Everything points to suicide. Tina Campenhausen knows the dead that she keeps secret from her colleague. Tina is caught up in her past when her sister, Jenny Hansen, whom she has not had any contact with for years, is at her door. Does Jenny have something to do with the death of the hotel guest? Tina gets into the biggest conflict of conscience of her life.
Based on one of the most spectacular series of bank robberies in Germany, Zwölf Winter tells the story of Klaus and Mike, two criminals who became friends in prison. When they happen to meet each other again after they have been released they begin to plan the perfect bank robbery, and it seems to work. For twelve years the two keep on robbing banks, always in winter. The police are in the dark for years. But they won't stick to their guns...
Steffen Vogt, aged around 25, is helping out at a German archeological excavation in Israel when he finds a 2,000-year-old skeleton holding the instructions for a video camera dating from the year 2003. The bones also show traces of the present day. His theory of a time-traveler who made a video of Jesus is laughed at by everyone, however, including Sharon, an attractive Israeli woman he adores. Although no one appears to believe him, his find certainly seems to have generated interest: Steffen is attacked shortly afterwards in his hotel room by strange men; then he discovers that the German embassy and the secret service are after him; and when his friend Dan is murdered, he goes into hiding.