Two Finnish PI:s are hunted by a gang specialized to counterfeit banknotes from Malaga to Finland and Mallorca and back. The counterfeit money printing plates are desperately searched by the gang and our heroes try to hide from them by travelling to Mallorca, where some of the local hoods try to kill them and retake the missing plates.
Justina urges Pete and Runt to get a job. As a result they meet an orphan boy named Otto while working as a park nannies. They offer to shelter the boy, but at the same time the father Antti, who has returned from the sea, is looking for his son together with Miss Raikas.
Eager young radio reporter Teräsvuori stages a one-man burglary into the Helsinki Art Museum, recorded on tape for a later broadcast by his friend Laakso. Things go awry when a gang of real criminals overhear their plans and book their heist to coincide. Teräsvuori gets caught but escapes from police custody to start his private investigations together with female radio colleague Eila.
Two children get involved in the adventure as the bustling caretaker Mrs. Aaltoska and crime reporter "Hawkeye" Lipponen start chasing the mysterious criminal league.
The S/S Vellamo heads to Alexandria with Kaarina, the daughter of the ship's owner Hallerman, on board. As Kaarina trades places with the family's housekeeper Marja, first mate Yrjö takes a liking to Marja whom he believes to be miss Hallerman. Meanwhile Kaarina, pretending to be a member of the cleaning staff, starts getting close with lower ranking officer Kalle Aaltonen.