In the middle of the Schaalsee runs the bureaucratically precisely defined "fluid border" between the FRG and GDR. One night a storm shifts a buoy of the border line. While the border and measuring troops from East and West meticulously try to restore order, two land surveyors throw their prejudices overboard and tear down the border between them for a short time.

A group of soldiers are haunted by a young woman they wronged in the past.

A B-52 bomber crashes and burns, killing one crew member, and destroying the four weapons the bomber carried, leading to some radioactive contamination that required a cleanup operation monitored by the Danish government.

Pola investigates on her own after her friend Tina has disappeared without a trace after a blind date on the Berlin Museum Island. Tina's profile on a dating portal finally leads Pola to her lover Sven. At the same time, Tina's husband Karl receives a sex video featuring Tina and Sven. A short time later, Sven is dead, and the bound Tina is released from his apartment. Everything points to Karl as the culprit.