Svenja Uhlig is found dead on the premises of a high school. She was pushed off the roof. The day before, she had celebrated her tenth graduation anniversary with investigator Kim Nowak and other school friends. Kim Nowak can no longer remember everything from the night, and she is withdrawn from the case. It is difficult for her to stay out of the investigation, which leads to conflicts with her colleague Jan Maybach. Mikko, Svenja's husband, was Kim's childhood sweetheart. When it is discovered that the two had sex on the night, he becomes the main suspect.