Betty gets a part-time job to earn money enough to get Barney a rocking chair. She runs errands for someone who she thinks is an elderly lady. So Betty disguises herself as an elderly lady as well with Wilma's help. The elderly lady, however is actually a counterfeiter gun moll named Greta Gravel and sends Betty to the store to buy small purchases with fake 100 dollar bills in order to get authentic money. Fred, Barney, and Wilma find out and help Betty get the counterfeiters captured.