The daughter of a lighthouse keeper runs away with a shipwrecked businessman to the city. But instead of her dreams, she ends up selling herself in the streets, until a painter finds her as an ideal model for his next painting.
Katariina, an orphaned girl from the north, travels to Helsinki to live with her distant relative Mauri, who has been appointed her guardian. The unpretentious child of nature irritates, amuses, and charms Mauri, who is accustomed to high society, and his bachelor friends.
Dentist Lauri Liesi is performing as a magician in the Hotel Metropol. Meanwhile, during his performance top-secret letters of engineer Arpila are stolen from his room. Mr. Liesi is then being accused of the theft. To clear his name he starts to investigate and search the culprits from the criminal underworld. With the help of a former circus man Romonen he begins to unveil the truth.
