Although the majority of the season two episodes were conceived during pre-production, as well as during the filming of the second season, other episode ideas, or scenes, were originally intended to be scripted for the first season. A scene involving Clark inadvertently using heat vision in his sexual education class was originally scripted for the pilot, but was cut when the budget became too large. That scene would become the inspiration for the season two episode "Heat". Since his initial performance as Ryan in season one's "Stray", Gough and Millar had hoped to be able to bring Ryan Kelley back to "Smallville". In season two they got their chance, with the intention to kill off the character, who was suffering from a brain tumor. Gough and Millar were initially apprehensive about how audiences would react to the death of a young teenager whose age was representative of the target demographic. For the episode "Ryan", the creative team wanted to show that Clark, even with all his powers, cannot save everyone; in this case, Clark's speed and strength are no help against the tumor growing in Ryan's brain. The episode is about Clark's trials of learning that life is not easy, and how those trials change him. "Lineage" was one of the original stories Gough and Millar pitched to the studio when they were first trying to get "Smallville" off the ground. The episode was designed to explain why Jonathan hated Lionel Luthor—having made a deal with him in order to be able to adopt Clark—as well as set up the character of Lex's half brother, Lucas, in the forthcoming episode "Prodigal". As he wrote the episode, per Millar's suggestion, Biller drew inspiration from John Sayles's "Lone Star" when writing the flashback scenes. In "Lone Star", to illustrate the moment of flashback, the camera would pan around until it revealed the past.