In modern-day Taganrog they find the record cards of war-era policemen. The FSB instructs Major Vitaly Polyakov to find the criminals-collaborators. During the Great Patriotic War the youth of Taganrog decides to create a Komsomol underground.
Enemy forces enter occupied Taganrog. Viktor Shvets gets a job in the commandant's office as a chauffeur under the name Gustav Schwartz. In modern-day Taganrog, Ukrainian saboteurs install a wiretap in Mostovoy's house.
In occupied Taganrog underground fighters are active sabotage work. In the modern city, saboteurs steal Polyakov's laptop with digitized cards of policemen.
The invaders respond violently to the sabotage of the underground, but the young resistance continues to fight. In modern-day Taganrog, FSB officers find out that the saboteur who stole the laptop has received a large sum from the bank.
The wounded German invaders decide to use the children as donors for blood transfusions. Underground fighters together with the Jewish tailor Samson Goldschmidt try to save the children.
Brandt learns of Gustav Schwarz's connection with Nonna and attacks her. Shvets swears revenge. Larisa Strepetova gives Peter information that the Germans are planning a roundup of Komsomol members.
Nonna is also involved in the underground. Meanwhile, a real hunt for the resistance begins.
Shvets must get hold of maps of the location of all enemy units. With Nonna they make a cast of the key of Brandt's office and steal the maps to deliver them to Rostov.
