Ep 16. Barrel of Monkeys

In season 8 episode 16 of Mystery Diners, titled "Barrel of Monkeys," restaurant owner Mark suspects his staff of playing pranks on customers during business hours. He hires Charles Stiles and his team of Mystery Diners to investigate the situation.

The Mystery Diners send in undercover operatives to pose as customers and observe the restaurant's staff. They witness an employee spraying cleaning solution on a customer's food, and another employee intentionally sending out cold food to customers. The Mystery Diners collect evidence of these pranks and report back to Mark.

With the evidence at hand, Mark confronts his staff and fires the employees responsible for the pranks. The remaining employees are retrained on proper food handling and customer service, and the restaurant implements stricter monitoring protocols to ensure these types of pranks do not happen again.

The episode ends with Mark pleased to have resolved the issue and grateful to the Mystery Diners for their help in uncovering the wrongdoing within his restaurant.