Professor Rafał Wilczur (Jerzy Bińczycki) was a successful surgeon in Poland in the early 20th century, whose wife leaves him with their small daughter for another man.
Suffering from amnesia, he ends up in a small village, working as a farm laborer for years and is known there as Kosiba.
He eventually starts healing the other villagers, and performs surgery on an injured young woman Maria (Anna Dymna).
He is told that his former wife died of tuberculosis shortly after leaving him, and the daughter ended up in an orphanage.
Maria then marries Leszek (Tomasz Stockinger), the son of a local nobleman.