In the aftermath of a tornado, Clark must find his missing father. Jonathan tries to keep Nixon from revealing the family secret, while Lex makes a fateful decision for his father.

A dangerous new power threatens Clark's relationships. But Lex's beautiful new wife -- who can control others -- may be an even greater danger.

Clark attempts to keep his secret hidden from his best friend after Pete discovers the missing spacecraft. A former LuthorCorp scientist gets closer to the truth about the ship.

Exposure to red meteor rocks wildly alters Clark's personality. Jonathan and Pete must take desperate measures to return him to normal.

Lana is entranced by a young man who leaves poetry for her at her parents' grave site. But she and Clark discover that his parents keep in chained in their basement.

Martha approaches her estranged father for help after learning that the family farm is in financial trouble. Lana discovers that her biological father may still be alive.

Clark confronts his parents about the truth behind his adoption when a woman shows up claiming to be his birth-mother. Lana approaches the man she believes may be her father.

Clark helps his young friend escape a facility where he is being studied for is telepathic abilities, but learns that he may not be able to save him from an even bigger threat.

Clark is concerned when a fellow student starts dating both Lana and Chloe, but the girls accuse him of jealousy.

Clark discovers cave drawings telling the story of his arrival on Earth, and attempts to save the site from LutherCorp.

Whitney's unexpected return to Smallville signals danger for more than just Clark's relationship with Lana. Lex becomes suspicious of his new girlfriend.

Lionel Luther and Martha Kent are held hostage by a band of criminals -- sent by Lex to bug Lionel's office.

Jonathan Kent becomes the prime suspect after Lionel Luther is shot. But Clark soon learns that Jonathan was by far the only person with a motive.

A parasitic worm infects Clark's friends, turning them into thrill-seekers -- and threatening to tear apart Clark's relationship with Lana.

Lex finds his long-lost brother, who becomes a pawn in the feud between Lex and Lionel. But young Lucas Luthor has plans of his own.

Martha falls deathly ill after exposure to meteor rock-infected mold spores. And when Clark begins to exhibit similar symptoms, Jonathan must take matters into his own hands to save his family.

A fantastical event at the cave gives Clark the ability to read the alien language, pushing him to seek out a world-famous scientist for information about his secret origins.

Clark meets a young man who believes himself to be an alien, and is hesitant to believe him -- until he demonstrates super abilities. Lex reveals his secret project to Helen.

Lex takes the law into his own hands when Helen's ex-boyfriend begins stalking her. Clark defends Lana from a bully, only to find himself being sued for injuring the man.

Jocks from Smallville High use airborn meteor dust to gain super strength. But when they find that they are unable to beat Clark, they target his parents. Lionel Luther makes a surprising offer to Chloe.

Lana is stunned when she comes face to face with her best friend, who died as a child. Lex discovers that his father has been funding meteor rock research.

Clark's burgeoning romance with Lana is interrupted by a voice declaring Clark's destiny to rule the Earth. Dr. Walden awakens with incredible powers, and tries to kill Clark to save the world.

Clark must make a decision about his future when a message from his real father tells him to leave Smallville. Lex and Helen's wedding day arrives.