The world-famous Swedish boxer Flosse travels to Italy to fight for the world boxing title. In Rome he meets the nightclub singer Lollo.

The burglar Karl Kilian Ledig tries to get his somewhat reluctant son Carl Gustaf interested in his "profession". He bring him along one evening to the sculpture Ulla-Carin von Knaake's house to break in and steal from her safe. Complications arise when Ulla-Carin and some of her friends unexpectedly come home and she imagines that Carl Gustaf is a model she has hired from a model agency.