15 passengers are found frozen to death in a bus. They wear festive clothes, but did not know each other. Sandra Winckler starts an investigation.

Where did the bus come from? A man frozen to death and a missing woman who just had a baby. The case reminds Officer Winckler of a case ten years ago.

At a wind turbine, the body of a young woman who just gave birth is found. Sandra believes another bus will be found in the surrounding area.

For safety reasons, Sandra may be taken off the case. She refuses to step down. Catherine thinks she found the killer, but Sandra is not so sure.

Antoine is kidnapped, probably by the unknown killer. Sandra and Catherine devise a plan to get Martin Souriau to lead them to the killer.

Sandra investigates the orphanage where the killer lived as a child. She has a list of names and decides to track all children down.

In the season finale, all questions are answered. Can Sandra prevent the wedding? Will Catherine find her missing baby? And who is the Minotaur?