 An Observer (either September or a different unnamed Observer) appeared in every episode of "Fringe", albeit sometimes only as a brief cameo.As a tie-in with the show, actors playing Observers appeared in the audience of other FOX network shows, including "American Idol" and the 2009 Major League Baseball All-Star Game.In creating the Observers, the producers had some idea of how they would be introduced into the show, starting as a background character and only becoming a significant figure by the midpoint of the first season.