Since architect Frank Richter's wife's death, their son Florian (7) is determined to see his dad marries to get hum an second mother. Durng a trip from Bavaria to uncle Maurice's monastery by Danube steamer, the young Cupid selects and fetches an ideal candidate, Gabriele Welser. Dr. Walter Kuntz, her fiancé, meanwhile travel along the Danube by sports-car and picks up a sassy hitchhiker to his taste.