The courage to preserve one's integrity in trying times.

A geologist engineer Yuliya disappears. Ablamov, an elderly engineer, organizes a rescue party to look after her in the mine galleries but they find nothing. Yuliya was last seen at a ceremony for award-wining miners. The newsreel crew was filming the event. Yuliya left in the middle of ceremony. Prodanov, a headstrong and quarrelsome engineer, had followed her. Suspicion falls on him. However, the film sequences shot at the ceremony reveal that Ablamov reacted suspiciously to Yuliya's exit. Detected as the murderer, Ablamov attempts to cross the border but is caught. Yuliya had discovered that the ore contained uranium. Ablamov had replaced the samples in order to prevent the development of the uranium ore deposit.

The university student Bobchev joins a youth brigade. The commander's council entrust Bobchev with a literacy course for members of the brigade. Velizarov and Monkata arrive in the camp to carry out sabotage. They place explosives on the dam, and attempt to win Bobchev over by means of intrigue. There is a storm: the camp is put on the alert. Everyone joins the rescue work at the dam. After a long struggle with Velizarov, Bobchev cuts the burning fuse of the explosive. The dam does not yield to the pressure of the flood. Everymen sing in Jubilation.