A supermarket is robbed. Commissioner Karl Jäger, who happens to be present, shoots the robber and is subsequently suspended from duty because the attacker’s weapon is not found. The incident also plunges Jäger into deep psychological problems. As a result, commissioners Lola Kraft and Jasmin Stein are called in when two bodies are discovered during the night of a class reunion at the Calw Hermann Hesse High School. All 29 party guests are considered suspects. When the investigators find out that their suspended colleague was a former classmate, his memories help advance the solution to the case, which has its origins in their school days.