This episode, titled "Bringin' Down the Haus," brings viewers to Glendale, Arizona, to find out what is going wrong with Haus Murphy, a Germen restaurant with a big pretzel as part of the decor. Brett and Rose Hoffman run the German comfort food restaurant, but recently brought in a nephew to help with the restaurant, but since he has been there, the problems have arisen. Brett knows that Gunnar is lazy, but now Charles will get to the bottom of the problems with him. The hidden cameras have been set up throughout with a control room in a nearby building.
The new waitress is a "Mystery Diner," and Gunnar has no idea. Gunnar was told to train the new waitress, and he gave her no instructions whatsoever. Gunnar has sat on his behind in the office talking on the phone, and when the new waitress went looking for him for help, he just got annoyed at her. While Brett and Rose watched the entire scene play out, they were totally disgusted with what they saw.
The wait staff was outside smoking, which is against the rules. Another "Mystery Diner" went in as a customer. He asked questions and had an expired coupon for food. He wanted to speak to the manager about it, but Gunnar would not take it. Rose stated that she would take the coupon. Another undercover guy played a beer distributor and tried to sell Japanese beer to the German restaurant and gave a good deal which went right into the back of Gunnar's car.
Brett is appalled that Gunnar is stealing from them. His waitress asks Gunnar about declaring tips, and he gives her illegal advice. The diner who wanted to use the coupon tried to send back the appetizer, and Gunnar gave him an ultimatum and told him to get out and not return.
When the Hoffmans have had enough, they call Gunnar into the control room to show him what they saw. Charles told him that the customer, the waitress, and the delivery guy were part of his staff. They are now fed up with him and his actions. He was fired on the spot and now feels betrayed by his aunt and uncle. Four months later, Rose and Brett are still looking forward to their retirement but continue to work. Gunnar returned the beer but will never be employed by them in the future, thanks to the undercover work by the "Mystery Diners."