Wealthy and ill Petr Kornel (Karel Hasler) is not pleased with the carousing lifestyle of his nephew. He stops supporting him financially and demands that he change his name. Out of gratitude Kornel bequeaths a substantial sum of money to his nurse Alice (Adina Mandlová) with the condition that she marries. Petr Suk (Hugo Haas), as the nephew is now named, visits the doctor. In the waiting room his X-ray is mistakenly switched with one of another patient's. On the basis of this he presently learns that he is seriously ill and has only one day of life left to him.
Curious citizens await the arrival of an important guest, the son of poacher, who became famous abroad. Begins celebration in his honor, but nobody knows that instead of the hero arrived cursory prisoner number 1313. He quickly understand how things are and decides to take the opportunity and very quickly gets into a new role.
