A film centered around a popular Finnish song book. Young lovers Pirkko and Pekka break off their engagement at the end of an evening spent at a dance restaurant. At home, Pirkko finds a songbook in her room, whose songs turn into musical scenes. The night watchman carries the songbook with him, and it ends up, via a sad prostitute, a police officer, and a night shelter resident, with Pekka, who is waiting for Pirkko's forgiveness and comes to pick up his fiancée.

Urpo, an alcoholic former priest, has been in prison for manslaughter. During this time, his partner Meeri has been forced to resort to prostitution. Ulla and Väiski, homeless alcoholics, bring Lauri, who has run away from a children's home, to Urpo and Meeri's care. Has the chance for a new life already been lost?

Due to the post-war housing shortage, Pirkko, who has nowhere to sleep, is given accommodation at the full-service guesthouse run by landlady Töttermanska. There she meets the other residents: student Eskoo, foreman Heikki, antique dealer Theodor, and businessman Roope, whose acquaintance with the beautiful Dolly draws the whole group into criminal activities.

Paavo and Eeva, two young people who have moved from the countryside to the city, meet a gang led by Kalle, who spend their time loitering and committing petty crimes. A fateful evening on a motorboat irrevocably changes the young people's lives.