Maria Thaler, the recently widowed landlady of an inn in the picturesque Weineck in the Wachau region, gives birth to twins. At the same time, kitchen maid Rosina also gives birth to twins in the same house, albeit illegitimate. Mayor Scherzinger exploits the growing rumor that quadruplets were born in the inn to market Weineck as a tourist attraction. With complete success!
The captain Paul Heider enjoys the reputation of a Danube Casanova.
