After graduating from the Faculty of Geology, Vasiliy Ruban goes to Transcarpathia, where he will take part in a prospecting expedition, the object of which is oil fields. A business trip of a young man turns into a quarrel with his girlfriend, who dreams of a graduate school in the capital. Despite the assurance of an experienced engineer in the absence of oil deposits, Vasiliy continues his search, which turns into an unexpected discovery of oily spots in the waters of the river. At the same time, the geologist meets Kseniya, a local girl who has won the heart of a man.