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.

After receiving numerous complaints from his staff that his recently promoted head waiter is not evenly distributing the pooled tips, the general manager of D'Cache restaurant in Los Angeles contacts Charles Stiles and the Mystery Diners to help him discover if there is any truth to the rumor. Charles sends in Destiny and Grant as a customer and a waiter, where they discover the head waiter is telling customers the card system is down, and pocketing the money. The waiter tries to set up Grant by stealing an entire bill payment, then asking Grant to fetch the bill. When confronted, the waiter tries to defend himself, stating the manager giving tips to people who haven't earned them is stealing. The manager doesn't buy it though and the waiter is fired.

When Mario, the owner of La Traviata in Long Beach, California, becomes concerned over complaints with respect to the quality of his fish, Charles and the Mystery Diners discover that a recently hired chef may not be honest about what's in his high-priced dishes. Mystery Diners Rob, Shellene, and Lauren go undercover to find out what smells fishy.

The owner of Pips on La Brea in Los Angeles named Derrick Pipkin has a problem with a waiter named Bob who claims he hurt his leg on the job the day Derrick was going to fire him for not doing his job. This former waiter has threatened a lawsuit. So to appease him, Derrick has made him a host. However, his lazy behavior has not stopped and Derrick wonders whether the injury is even legitimate. Derrick contacts Charles Stiles for help and Mystery Diners Shellene, Lukas, and Tracey go undercover to see if Bob is faking his injury. While posing as a damsel in distress, Tracy helps to prove that Derrick is right about Bob. During the confrontation, Bob is finally fired and told to take his leg brace with him. The narrator revealed that Bob "kept on walking" and Derrick hasn't heard from Bob since the taping of this sting. Pips has finished it's relaunch where business has never been better.

Ali, owner of a Moroccan-themed restaurant in California called Marrakesh, seeks the help of Charles and the Mystery Diners because he believes his manager may have a gambling problem outside of work that's affecting his ability to do his job. Mystery Diners, Rob, Scarlet, and Loree go undercover to see if the manager's extracurricular activities are taking a toll at work.

Johnny, owner of Pina Pizza House in Downey, California, seeks the help of Charles and the Mystery Diners because he believes his "frat-tastic" college-enrolled waiter may not have his best interests at heart and that he may be taking the party off campus and into his restaurant. Mystery Diners Grant and Jill go undercover to see if the waiter is taking his job as seriously as he claims to be taking his classes.

George, the owner of Los Angeles hot spot Ca' Brea, has recently received a few complaints that are surprisingly not related to the quality of his food or his wait staff's service, but about his valet service. Charles sends Mystery Diners Tracey and Hank undercover to show George just how detrimental a bad valet can be to a restaurant's business.

Chef Marc, owner of Parma in Las Vegas, contacts Charles and the Mystery Diners for help after noticing disparities in sales receipts and inventory with his high-end Italian deli meats. Mystery Diner Shane goes undercover as a busboy and discovers one of Marc's employees is down on his luck and may be using restaurant supplies for personal gain.

When Will, co-owner of Whiskey Dick's in Las Vegas, becomes concerned over a steady decline in female patrons, Charles and the Mystery Diners come in to investigate. Mystery Diner Shellene goes undercover as a waitress and learns that the manager is serving more than just drinks from the bar.

Scott, the owner of Rhythm Kitchen in Las Vegas, suspects his sophisticated, but slightly arrogant, wine sommelier is somehow negatively affecting spirit sales. But could he also be selling his own wine to customers and keeping the profits? Charles sends Mystery Diners Chelsea and Hollie in as customers to see if something smells rotten.

Janaya, the general manager of Putter's Bar & Grill, contacts Charles for help after noticing unusually low sales during the graveyard shift. The Mystery Diners go undercover as customers and discover that the overnight bartender is running his own bar out of Putter's called "the Junkyard." During the confrontation, the bartender recognizes Charles and takes his leave from the restaurant while telling the pursuing cameraman to stop following him.

After Nico Santucci, owner of Capo's Speakeasy's, hears complaints that his brother/manager Dominic is acting inappropriately with guests, he calls Charles to investigate. The Mystery Diners go undercover and find that he is hitting on a lot of the female patrons. There is even a bigger problem with a disgruntled waiter who is stealing money and supplies from the restaurant. During the confrontation, both Dominic and the waiter are fired. The narrator revealed that Dominic is behaving himself. The former waiter has apologized for his actions and found employment elsewhere.

When two employees who recently broke up disrupt staff harmony and start effecting sales at Marche Bacchus, owners Jeff and Rhonda seek Charles for help. The Mystery Diners go undercover to get to the bottom of this lovers' quarrel.

When Adam, owner of Via Brasil, is concerned that meat sales aren't being reflected in his register, he calls Charles for help. When the Mystery Diners go undercover, they discover the manager is doing a lot more than just giving away free steak.

The owner of Catharsis in Miami, Florida receives complaints about inappropriate touching and theft of items during the restaurants "Dining in the Dark" event. The targets are three newly hired servers (two waiters, and one waitress). The Mystery Diners head into the restaurant and discover that the new waitress and waiter have created a game by screwing with both the customers and food and stealing from them. The waiter and waitress are both fired during the confrontation. The narrator revealed that the former servers have gone their separate ways. The remaining new server has been promoted to head server.

The female owners of Cheeseburger Baby in Miami ask Charles to investigate a waiter who is a former an ex-con over reports of theft of money from the cash register. The owners hired him in order to give him a second chance at life. The Mystery Diners point to big problems: their waitress is behind the theft and falsifying evidence to pit the customers and owners against the ex-con waiter over his past as her scapegoat. Being confronted, the waitress tries to defend herself, but the owners are fed up with her lies and force her to confess. She eventually does while giving them the money and they fire her while denying a second chance for her. The owners apologized to the ex-con waiter for believing that he was responsible for the theft. The narrator reveals that the former waitress was never heard from again. The ex-con waiter maintained his loyalty and celebrated his 10-month anniversary at Cheeseburger Baby. The owners implemented a new register to prevent thefts.

The namesake of George's in Miami think his staff is going too far with the party atmosphere after noticing significant revenue loss. He had a right to be concerned because his manager and bartender has been over-serving women free shots, letting customers drink beer from a beer bong, and threatening to burn the whole restaurant down with one of them wearing George's Napoleon hat. During the confrontation, they are both fired by George. The narrator revealed that the former manager and bartender have found employment elsewhere. The waiter has begun training to be a manager. Only George is allowed to wear the Napoleon hat.

The owner of Garcia's Seafood in Miami notices an unusual low amount of Crab Claws, and wasted product. The team finds out that a fisherman whose father worked for his company a long time ago has been selling the catch to another buyer and a prep cook is improperly filleting fish. The fisherman is fired and the prep cook is told to improve his filleting skills. The narrator revealed that the former fisherman is working at another fishing company. The prep cook is no longer wasting product. The owner installed an expensive security system to watch his restaurant from his office.