Orma Aunio

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.

A closed room mystery begins when an infamous tycoon is found dead in his bath tub. The famous police lieutenant Palmu is summoned to investigate.

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.

Justiina pushes Pekka and Pätkä to take painting lessons after realizing that art can be a way to earn a living. With the help of the yard children, a painting is created that wins first prize at a contemporary art exhibition. In the meantime, the men, along with their assistant Miss Kaihokielo, have been charged with art theft. After the misunderstanding is cleared up, the Puupääs use the art prize money to convert the house's bomb shelter into a children's clubroom.

The headmaster of a private girls' school is doing her best to maintain strict discipline in the school. In addition to the loosening morals of the students, the warm relationship between two girls is a causing concern.

A story of a mink coat passing from one owner to another binding their fates.

A man's body is found on Tähtitorninmäki in Helsinki. Palmu starts to investigate the case, but the scandalous newspaper story causes problems for the police.

The last black-and-white film in the Niskavuori series of movies.