Tar Steam Princess Armada travels along Lake Saimaa to St. Petersburg and back during the years of Russian rule over Finland. The ship's crew gets tired of their sophisticated coffee maker and replaces her with Roma girl Veera, who has escaped from an arranged marriage. On the way back, mysterious passengers appear on the ship.
Three sailors rescue Carmen, who has fallen into the clutches of the white slave trade, and also manage to destroy a drug gang.
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.
