Diane wants to get in touch with her teenage-self so that she can understand what Amy and her new client, Howard, are going through. Wayne has invented a machine where you can see yourself in the past. When the electricity goes out, Diane is stuck as a teenager. Now Wayne must fix the machine and the family has to deal with Diane and her rebellious self.

Wayne feels overwhelmed with the demands of work and his family so he invents something that will make him go from place to place in seconds. He sets the level on high and somehow travels at the speed of light. Jennings finds a copy of the invention and is traveling fast too and playing tricks on people. The two of them get stuck at hyperspeed and must use another Szalinski invention to slow their molecules.

Wayne accidentally blows up the mayor's car in front of the mayor which upsets Diane, who wants to run for the school board, so he goes back in time to redo things. He accidentally goes back to the time of "the barbarians". When Wayne comes back he accidentally brings the "Barbarians" with him but when he tries to send them back the machine is broken. The barbarians become involved in the school board race when they are convinced that Diane's rival is an evil Norse god.