Pekka Puupää and Pätkä, who return to Helsinki from an unsuccessful variety show tour, are forced into refresher training, where they are trained as frogmen. During the diving exercises, the friends encounter the mermaid Helmi, whom they help into the bathtub at home, to Justiina's shock. The friends, who have become civilians, eventually end up on a plane bound for Suez, being cornered by UN soldiers.
Marjatta lives in poor conditions in Tampere with her widowed father Arttu who works as a factory worker. Marjatta gets to know engineering student Pauli whose constantly worsening mental health problems and jealousy become a threat to Marjatta and her close circle.
In the remote village of Hurula, the mistress of the house has forbidden her henpecked husband from enjoying himself and playing the accordion. The ceremonious host Ernesti courts the Hurulas' daughter Pirkko to be his wife. However, she falls in love with the village's new cantor Pelle, but multiple misunderstandings have completely complicated matters.
