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.