Diamonds.

Young geologist Sergei Nesterov, having returned from the army, intends to continue his work, interrupted by the war, on exploring industrial deposits of Ural diamonds. His enthusiasm surprises his boss, puts his fiancée Varvara in an awkward position, and gives other geologists a perfect excuse to mock him. But he is warmly supported by the district committee secretary Salomatov. Sergei steadfastly pursues his goal and, in the end, finds the richest diamond deposits.