Series developers Al Gough and Miles Millar wanted to set up Lex's "mental illness" early in the season, as it would be something that Lionel would take advantage of in later episodes of season three. In order to accomplish what they wanted, Gough and Millar introduced Lex's imaginary friend "Louis", who appeared on the deserted island with Lex following his plane crash in the season two finale. They had Rosenbaum pull what they referred to as the ""Fight Club" gag", where he believes that he is fighting Louis, but in reality he has been fighting himself the entire time. This would culminate in the episode "Shattered", where, as Mark Verheiden explains, the episode was set up like something out of the film "Gaslight", where the audience believes that Lex is being driven insane.