Colonel Velyaminov begins to suspect that Yampolsky is not who he claims to be and that he might be the saboteur; Urusov sends his scouts to the commander of the partisans in an effort to shed light on Kardash's past.

A big division of the Soviet troops gets into the encirclement of the Germans; the only connection with big land is a narrow isthmus; Germans prepare a breakthrough; there is a dangerous saboteur among the Russians.

Scouts are sent to another partisan detachment where they see that the camp is empty, all are killed; in the distance, there is a knock of axes: saboteurs pretending to be partisans are chopping wood to put log on the road for German tanks.