Shortly before Christmas, a strange piece of evidence and an ancient book drive the young detective Carolin Arends to reopen the mysterious murder case of Alexander Michalski. She doesn't yet know that her greatest enemy is time itself and that she is already in the perpetrator's sights.

The childless sisters Regina, Anja and Susanne are outraged. Their wealthy mother is determined to become a grandmother and offers her fancy villa as a reward for the first of the three daughters to give her a grandchild. But Anja has completely different plans: she is going to emigrate to Brazil with Karin, the love of her life.

Everything seems to be going according to plan for graduate engineer Oliver Berger. He has only just landed a lucrative contract for his employer when he is already entrusted with the next major project. He willingly puts up with constant trips abroad and working through weekends. Meanwhile, his wife Lena and his ten-year-old son Moritz wait for him at his apartment in Erfurt or at the weekend house. Berger has never worried that his marriage might suffer as a result of his job. So he is all the more stunned when Lena leaves him at the drop of a hat. Suddenly, Berger is a single father.