When the pictures from Bergamo in Italy go around the world in spring 2020, even non-medical people know what the word pandemic means. The previously unknown Coronavirus is spreading rapidly across the planet. Four days later, exit and contact restrictions also apply in Germany. Since then, the life of the Konstanz intensive care physician Dr. Carolin Mellau and her family on their heads. The female doctor becomes a member of the crisis team and is on duty around the clock to prepare the clinic for the impending emergency. As an anesthesiologist intubating those infected with COVID-19, she herself carries a high risk of infection. Meanwhile, her husband Stefan has to cancel his concerts as a musician, is no longer allowed to teach his music students and is suddenly sitting at home without an income. Teenage daughter Luzy is not allowed to see her Swiss boyfriend because the border is closed. She and brother Tim cannot go to school. But the worst case for the family is yet to come.

An excursion boat on Lake Constance. Good-humored passengers celebrate at a costume party. In the middle of it all is Elena Barin on the day before she takes up her post as head of department at the Constance criminal investigation department. She is traveling as a tourist - until the moment she notices a weapon on a passenger.

Nine-year-old Max moves to Geroldseck Castle, together with his mother, who takes up a position as a geriatric nurse there. Apparently a shrewd thief is up to mischief here. His mother is suspected, she is threatened with dismissal. Therefore, together with the three residents of the old people's home at table no. 7, Max does everything possible to convict the real perpetrator.

Eva is struggling to live happily with her autistic son Felix. The two are inseparable, but Felix's frequent outbursts of anger, the constant problems at school and his fear of strangers are almost impossible for Eva to cope with. One day when Felix accidentally seriously injured Eva, suddenly nothing is the same as it used to be.

The unsuccessful writer Max Rhode is a law-abiding citizen. But what Max doesn't know yet: In a few days he will commit a crime so horrific that it is hard to imagine for a human being.

After two years, after a tip from Shukshin, Blochin finally got the chance to lure the child murderer Kyrill to Berlin. In addition, the self-proclaimed avenging angel takes his lover Pheline hostage, who is found shot shortly afterwards.

Felix is looking for a friend and discovers the 'Fulgidusen', the little lights of the forest. But the village of the Fulgiduses and thus also the secret of the forest are in great danger ...