S1, E4: Amy develops a crush on Mr. O'Donnell, her handsome 37-year-old history teacher. She uses Wayne's time-travel machine to transport herself to 1976 where she hopes to meet up with the teenage version of Mr. O'Donnell and make some history of her own. Wayne travels back in time to rescue his daughter, but the Szalinski Time Hopper (patent pending) malfunctions and the two are stuck in the past. With some help from a romantic memory, Diane and Nick repair the machine -- just in time -- and the Szalinskis are reunited in the present.