David and Maddie do some moonlighting of their own for a debt collection agency when the agency is short of money. They discover that one of the company's clients has been killed, but when they return with the police, the body has disappeared and a completely different man is at the scene claiming to be the client. This leads the duo to become involved in a CIA investigation, strange clues, international espionage and an assassination plot to kill a very important Chinese man at a banquet. But the main problem is that they haven't got the idea who is the Chinese guy because the only description they got is found in a message that says "a man with the mole on his nose". This leads them to the banquet posing as waiters and trying to solve yet another mystery.
