 Mme Arrieu is the owner of an apartment building in Paris, where she lives with her three nieces, all very respectful. Then, Elvira, a lady who paints nudes, gets behind in her lodging payments. Elvira, wishing to impress a prospective customer from the United States, asks Mme Arrieu to let her use her (better) apartment, to receive him - just for a couple of hours. The lady refuses, but then she must leave for a shor spell... Temptation is too big. A couple of name plates on the door bell are changed and everything will go smoothly. Or... is it?