 " Burns ' Heir " was the first episode in which <unk> Richdale received a writers ' credit , although he was a part of the show 's staff for several seasons . When he was starting out as a writer on the show , Richdale was told to come up with some story ideas and he came up with the basic plot off the top of his head . David Silverman was originally going to direct the episode , but he was so swamped with his work as supervising director that it was reassigned to Mark Kirkland . While the Simpsons are at a movie , there is a parody of the THX sound Deep Note . During that scene , a man 's head explodes in a reference to the film <unk> . The THX executives liked the parody so much that the scene was made into an actual THX movie trailer , with the scene being redone for the widescreen aspect ratio . 
