Episode Title:The Substitute.Episode Description:Lord Fear and Pigface kidnap Mark's science teacher, Mr. Cheseborough, and replace him with Lady Illusion in disguise, as part of a trap to destroy Mark. In class, Lady Illusion puts Mark and Chuck in detention. Realising something is amiss, Mark searches the carnival for the real Mr. Cheseborough but is cornered by Pigface and Dirty Rat, Ace rescuing him. Samantha instead finds Mr. Cheseborough, discovering he is being used as a sideshow.