Original: Some shows feature a special guest star ( e.g. , Don Drysdale on a season premiere episode of The Brady Bunch or Jerry Seinfeld on a season premiere of 30 Rock ) ; others might have multi-part '' adventures , '' such as the Bradys ' family vacations to Grand Canyon and Hawaii .
Simplified: Introductions of new characters , frequently to boost the ratings of a veteran show , two examples are John Doggett in season eight and Monica Reyes in season nine of The X-Files .