As he speaks indistinctly, Rochus Valerian, the caretaker of the apartment building, understands that the reservation should be made for a certain Karla.
So when Karl arrives, he moves into a women's apartment, which his new roommates Karin and Elfi are not very enthusiastic about.
However, the young woman has a problem, since she is once again late for work, she is fired on the day Karl arrives.
Out of necessity, Elfi accepts the job, even though she hates serving drunk men in provocative clothes.
Elfi has to work while Karin has found a lover, the mad inventor Thomas Butterfield jr., who leaves his girlfriend and benefactor Mabel for her.
It is also he who warns the unequal trio a little later that the moral police have found out that Karin and Elfi are sharing the apartment with a man.
Without further ado, Karl is disguised as Karla and plays his role so well that the vice inspector doesn't notice the trick.