It is early 1943. Following their defeat at Stalingrad, the Germans are plotting their revenge. A Soviet commando unit is dropped into the occupied territory. But all are killed, except for a young radio operator named Katya. Mukha finds her in the forest and hides her in the village where he lives with Alona. To maintain secrecy, they pretend to be husband and wife. Underground activists in the city learn of the radio operator. Grigory, who serves in the police, is sent to liaise with her. Feelings flare up between the radio operator, Katya, and Grigory. But Grigory is still trying to mend his relationships with Dasha and Alena. He fails to do so. Moreover, a mutual attraction develops between Alena and Mukha. And Dasha, having lost her child and been saved from execution by Walter, ends up at his house. Walter proposes that Dasha become his wife, but Dasha refuses. Soviet intelligence officer Anton Kovalyov tries to establish contact with the underground through her. He serves the Germans under the name Johannes Weiss and has access to secret information. He can find out and report to headquarters where the main German offensive will take place.

Dasha, in an attempt to help the Soviet intelligence officer, agrees to stay at Walter’s house, accepting his help but trying not to reciprocate his feelings. Grigory wants to fight the Nazis and is eager to go into battle, but he is ordered to count the trains heading for the front and pass the information on to the radio operator, Katya. The primary task is to determine where the Germans are preparing their offensive: in Belarus or near the Kursk Bulge. Grigory protects Mukha, Elena, and the radio operator, Katya, from the excessive attention of the local police...