Grete Hansen is looking for a job at "Morgenbladet". Here she meets the woman seducer Vilmer, who wants Grete to meet him the first night out on the town and Bob, a young man who plays a private detective. When Bob reads that there are a number of counterfeit 100 kroner banknotes in circulation, Bob and Grete decide to catch the thief. First, they commit burglary at a police officer whom they suspect to be a counterfeiter. Later, they play servants with another suspect. Then Grete discovers something suspicious in Vilmer - she shadows him to a scary house.