Soviet propaganda film on the struggle against counter-revolution in Tambov region in the first years of Soviet power.

The film recreates the heroic epic of the defense of Sevastopol in 1941-1942. The fall of 1941. Having broken through the defense at Perekop and seized Crimea, the fascist troops begin the siege of Sevastopol. The Soviet fleet is withdrawn to Novorossiysk. For the defense of Sevastopol remained only guns of ships, coastal batteries and several detachments of marines, the defense is led by General Petrov.

Two foolish and frivolous guys cause suffering for the whole youth union at the factory. It was already decided to dismiss them when are taken under the wing by Nadia Berestova, a diminutive funny woman, known as the popular one at the plant. At first, Nadia took it with reluctance and apprehension, but gradually this commission became the most important thing in her life.

The team of diesel locomotive builders is struggling to increase output. More efficient welding methods are needed, but all the efforts of Andrei Kostrov and his comrades to design a new welding machine are in vain. On this ground in the brigade disagreements arise. A group of skeptics persuades Andrei to abandon the fruitless search and go to work at the former site. Among the doubters is Kostrov's wife Taisia.