Mystery of the Royal Wedding is the seventy-seventh episode of Mister T: The Animated Series. It is inspired by Entertainment Tonight and the wedding of Prince Charles and Princes Diana and guest stars former Entertainment Tonight host Mary Hart.
Entertainment Tonight is covering a wedding between the Crown Prince of a country and a noblewoman in that same country. Mr. T and the team investigate when they uncover a plot to sabotage the wedding. With help from former Entertainment Tonight host Mary Hart, can they stop the saboteurs?
In the introduction sequence, Mr. T and the team appear on Entertainment Tonight where they are being interviewed by Kevin Frazier, who is the host of the show. Mr. T notes that you should not take an impending marriage for granted and the team starts talking about the Mystery of the Royal Wedding.
Mr. T and the team are in Mankovia for the wedding of Prince Edward, the Crown Prince of Mankovia, and his bride Karen, a member of a family of nobles, who is a friend and a former member of the team. The whole thing is being covered on Entertainment Tonight. They are greeted by its former host Mary Hart who is on vacation. That night, a giant statue seems to come to life and threatens the wedding. Mr. T wants to call Mystery, Inc. for help, but they are busy solving a mystery with Jonny Quest. So they end up doing the investigation. At first, Robin suspects Karen because she is nervous about the marriage which is on international television. Vince does not think so. Another suspect is soon uncovered. He is Lord Hagenthal, a Mankovian nobleman. Jeff and Kim discover that he is a controversial figure in the Mankovian Parliament. Woody suspects that Lord Hagenthal might be behind the attack. Mr. T and the team with Mary's help sneaks in and discover a conspiracy to sabotage the wedding, massacre the Mankovian Royal Family, and take over the country. The next day, Mr. T and the team show up just in time to stop Lord Hagenthal and his henchmen. A riot breaks out, and Lord Hagenthal escapes in the "living statue", which is really a robotic exoskeleton. While Mary Hart gets the police, Mr. T and the team chase Lord Hagenthal. Using a fire hose, they catch Lord Hagenthal. Mr. T and the team are thanked by the Mankovian Royal Family who present them with an award.
In the closing sequence, Mr. T explains that Lord Hagenthal was eventually convicted and given the death penalty. His execution had just happened. He and the team then turn to the camera and point out that if a person is getting married, it is best not to take that upcoming marriage for granted because there might be some problems.