The fourth season of "HSMTMTS" will mainly focus on the making of "High School Musical 4: The Reunion" as the entire East High drama club learns that they will soon participate in the movie as extras. Within the realm of the show, everyone from the original "High School Musical" cast is supposedly returning in order to make the final film, but we don't know for sure whether or not every iconic character will actually be featured in the fourth season.