Свет в окне

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.