Lionel is sentenced to prison for his parents' murder in season four. Lionel attempts to switch bodies with Lex using a stone from Clark's homeworld of Krypton but Clark intervenes and Lionel switches bodies with Clark instead. When he and Clark switch back, Lionel discovers his terminal liver disease is healed. Lionel is released from prison by Genevieve Teague (Jane Seymour), and begins searching for three stones of knowledge. During this quest, Lionel falls into a catatonic state after being uploaded with Kryptonian knowledge. Lionel recovers in season five when the Kryptonian artificial intelligence Jor-El takes over his body to speak with Clark. With Jor-El guiding him, Lionel begins helping Clark by making excuses for Clark's behavior and unexplained disappearances throughout seasons five and six. Season seven revealed that Lionel and three other wealthy families formed the secret society Veritas to protect an alien visitor known as the Traveler (Clark). When the secret is uncovered, Lex murders his father, realizing he has been covering up the Traveler's existence.