In season two, Lionel moves from being recurring figure to a regular character. This season features the gradual unveiling of Lionel's increasing involvement with the characters of the show. It begins with more direct involvement when Luthor hires Martha Kent as his assistant, and then indirectly when he becomes the conservator of the Kawatche caves and tries to unlock the mystery of the symbols on the cave walls. During season three, Lionel becomes the villain of the show when he tries to discover Clark's secret and drives Lex into a psychotic breakdown. This allows Lionel to use electroshock therapy on Lex to erase his knowledge of Lionel's co-opting of Morgan Edge to kill Lionel's parents for their life insurance. The creative team experimented with Lionel's character in season four, creating a storyline in which Lionel is reformed. Executive producer Greg Beeman said the character development failed, and as a result Lionel returned to his normal self. John Glover found playing Lionel as a straight arrow was "boring".