The teenager was admitted to a specialized school for children with lung diseases. The teacher deliberately opposes the newcomer to the present time leader. This causes tension among children. The conflict worsens when a new boy tries to gain the trust of the collective by dishonest means.

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.