("Teacher's Teacher"), the class's original teacher Mr. Thomas (Roscoe Lee Browne) had returned to Fillmore High, seemingly ready to return to the IHP class once Mr. Moore's tenure ended. After observing Mr. Moore's unorthodox teaching methods for most of the episode (much to Charlie's chagrin, as it also made apparent how much he would miss the IHP students), Mr. Thomas ultimately reveals he had no intention to return but came to observe Mr. Moore after hearing concerns about him from Dr. Samuels. Seeing Mr. Moore in action, Mr. Thomas gives him his blessing, leaving Mr. Moore to become their full-time teacher, knowing the IHP will be in good hands. Throughout the first season, Mr. Moore attempted to get the class involved in more than just their studies, encouraging them to play volleyball and make a music video for the school's time capsule (this marks the first foray into the fondness of Head of the Class for musical production numbers). At the same time, the class brought Mr. Moore into the present, acclimating him to the importance of personal computers. Near the end of the season, the IHP faces their Russian counterparts in an academic tournament, foreshadowing their famous trip to Moscow in season three. Season 2 (1987–1988) Season 2 began involving the IHP in the school as a whole, with Mr. Moore involving the class in the school literary journal and encouraging a lampoon of the school newspaper. Mr. Moore also decides to put on a school production of the musical Grease, and encourages the IHP (who are initially reluctant) to participate, alongside other Fillmore students. While first season had some episodes that showed Charlie's personal life outside school, these become increasingly rare as the series continues. In season 2 (and thereafter), episodes consistently focus on the lives of the IHP students, with only a very few focusing specifically on Charlie; this is the last season in which we see Charlie's apartment. Season 3 (1988–1989) "Mission to Moscow" In 1988, Head of the Class broke new ground as it became the first American sitcom to be filmed in the Soviet Union with an episode filmed entirely in Moscow. The IHP is invited to come to the country for a rematch of the academic meet that happened in season one, which ended in a tie. The class has a lot of experiences while in Moscow: Dennis and Arvid take an interest