Season 1

When the owner of The Groves Bar & Grill becomes concerned over a large loss in food and supplies, the Mystery Diners go undercover with hidden cameras as new employees and customers, suspecting that a recently hired chef may be plotting more than just the items on the menu. During the sting, they reveal that the newly-hired chef is running his own catering business and using the restaurant's kitchen and supplies to run it, making business at The Groves suffer, with customers waiting extensively for their orders. The owner, as well as Charles, confronts the chef and fires him. The narrator revealed that the former chef has gone out of business without his own overhead. The owner has his food and supplies all in check, with The Groves having an improvement in business.

Brett and Rose, the husband and wife owners of German restaurant Haus Murphy, disagree on almost everything, particularly the hiring of Rose's nephew as their new restaurant manager. Fearing he is unqualified for the job, the couple hires Charles Stiles and Mystery Diners Danny, Chris, and Deanna to go undercover and show them just how incompetent their nephew truly is. After the proof is shown, this leads to the confrontation where Rose ends up having to let her nephew go from his employment.

After losing thousands of dollars in unaccounted alcohol and hearing rumors of late-night staff parties, the owner of Big Earl's Greasy Eats contacts Charles Stiles and the Mystery Diners for help. Mystery Diners Shellene and Chris go undercover as a waitress and flirty customer in hopes of scoring invitations to an after-hours bash.

After receiving numerous bad service reviews and noticing a 30 percent decline in revenue, the owner of Caffe Boa contacts Charles Stiles and the Mystery Diners to help him find the cause of his problem. Mystery Diner Danny goes undercover as a waiter and discovers three problem employees: waiter Brad, waitress Gwen, and waitress-in-training Sophia. Gwen, despite calling owner Jay a douchebag, turned out to be a model employee and gave excellent service. Brad was not necessarily a bad waiter, but he lacked confidence and had a bit of a temper. Sophia turned out to be the biggest problem where she drank on the job, ate food off of customer's plate, and was rude. During the confrontation, Jay praised Gwen, told Brad to be more confident in his abilities, and fired Sophia. The narrator revealed that Sophia has found employment elsewhere. Brad took a wine appreciation course. Gwen was promoted to head waitress. Profits and service are back to normal at Caffe Boa.

The owner of Amaro Italian Bistro seeks the help of Charles Stiles and the Mystery Diners because he believes his manager is acting inappropriately with the staff and picking favorites based on appearance. Mystery Diners Destiny (who is Charles' daughter) and Sarah go undercover and interview for a new waitress position to see if the manager will hire an attractive waitress over a qualified one. This is proven true when the manager gets flirtatious with Destiny much to the annoyance of Charles. The manager has also attempted to poach the staff by offering them a job at his and his brother's own restaurant. During the confrontation, the manager gets into an argument with the owner and Charles which ends with him quitting. The narrator revealed that the former manager and his brother were unable to continue running their own restaurant after two months and both are seeking employment. The owner has hired a new manager and business has improved greatly.

Charles Stiles and the Mystery Diners descend upon The Blue Moose where longtime chef "Grumpy Tom" has a knack for disrespecting everyone in the place including the newly installed second-generation owner. Mystery Diner Jessica goes undercover as a waitress to prove just how grumpy Tom is and how his attitude negatively affects business.

A pub owner in Los Angeles suspects that one of her bartenders might be over-pouring for customers, giving away too many free drinks, and over-tipping himself. To find out, she calls in the Mystery Diners who outfit the bar with hidden cameras and go in undercover to see what is really happening when the boss is away.

Mystery Diners goes undercover to see whether this brother is a keeper.