Junior Lieutenant Maleshkin, an unshooted graduate of the school, commands the crew of the self-propelled gun SU-100. All the subordinates of Maleshkin are older than him and much more experienced. The authority of the young commander is tested at every step, he quarrels, then reconciles with his crew.

In a small town hospital, former partisan Korotkevich has been lying in bed for 20 years. As a result of brutal torture in the Gestapo, he lost his memory. Psychiatrist Kondakov succeeds in treating Korotkevich, and his memory returns. Now, with Korotkevich's help, it becomes possible to expose the traitors who betrayed and destroyed the partisan squad during the war.