Veliky Ustyug at the beginning of the 17th century. Semyon Dezhnyov falls in love with the daughter of a rich merchant — Avdotya, but the groom is poor. The girl's father sets a condition: Dezhnyov must go to Siberia and get rich — only then will he receive consent to marry. Dezhnyov agrees and leaves for Siberia. Although he passes the test, he does not return to Avdotya. He finds a strait "from a warm sea to a cold one": from the mouth of the Kolyma he swims to the Pacific Ocean and opens the strait between the continents.