Perry White, a once promising journalist whose career was destroyed by Lionel Luthor, arrives in Smallville in search of alien stories for a tabloid news show. In spite of being constantly inebriated, Perry believes he has witnessed Clark using his extraordinary speed, so he devises a dangerous scheme to expose Clark's superpowers. Meanwhile, Lex learns that Perry has powerful incriminating evidence of Lionel's shady past.

After Pete refuses to throw a street race, the thugs that run it threaten his life, so he asks Clark to use his powers to stop them. Furious that Pete would put himself in this position, Clark must figure out a way to save Pete and still protect his secret. Meanwhile, Jonathan begins to suffer the consequences of his deal with Jor-El.

Lana reads a spell book belonging to her 17th century ancestor, the witch Isabelle, and becomes possessed by her spirit. Isabelle resurrects her other two witches and together they seek out the kryptonian crystals, using their magic to render Clark powerless.

Clark is approached by Met U for recruitment and meets Geoff, a former Smallville resident. It soon becomes apparent that he is using his powers to paralyze anybody who gets in his way...including Lois.

When a boy who can make people lose their memories robs the Talon, Clark goes after him but gets total amnesia. Chloe finds out what happened and has to tutor Clark in the use of his superpowers and make sure he doesn't accidentally reveal his secret. While Clark, Chloe, and Lois try to track down Kevin, Clark takes advantage of his "new life" to ask Lana on a date. And Lex tries to turn Clark's memory loss to his advantage by getting him to reveal the secret of the caves.

Jonathan's oldest friend, Senator Jack Jennings, comes to Smallville looking for support in his re-election campaign, but is framed for the murder of his mistress, requiring Lois to go undercover as a stripper.

Clark discovers that the new assistant at the Daily Planet, a bespectacled, bumbling woman named Andrea, is actually a mysterious female vigilante who stalks Suicide Slum. Her path crosses Clark's as they both seek the same criminal. Meanwhile, Clark's bottled-up grief threatens to get the best of him and LuthorCorp experiences a shakeup.

Distraught over her break-up with Clark, Lana goes to a rogue medical student who experiments with a dangerous kryptonite-based serum that allows people to flat-line but see their dead loved ones. Lana attempts to see her dead parents using the serum and when Clark returns from Honduras to help her, the doctor injects him with the serum and Clark speaks with his dead father...who warns him that Lionel knows his secret. Meanwhile, Lionel continues working to get closer to Martha, and Lex has a near-death vision of his mother.

Lex and Oliver Queen return to their old prep school for a reunion, but Oliver's old friends (and Lex's old enemies) start dying in mysterious accidents. Meanwhile, Clark learns that someone... or something may have left the Phantom Zone with him.

Lana and Lionel have a secret meeting, after which Lana is shot. While Jimmy is observing photos of the encounter, he is knocked unconscious. While unconscious Jimmy dreams about what life in Smallville would have been like in the 1940s. Clark is a reporter at the Daily Planet, Lana is a siren who planned the demise of her magnate husband Lex, and Lois is a singer at a bar that Lionel owns.

Unexpected guests crash Chloe and Jimmy's wedding; Oliver thinks he has found Lex and sets out to confront him, but he is shocked to find Lana instead; Lois and Clark grow closer.

Jor-El mysteriously arrives at the Kent farm searching for his son, Kal-El, but meets Chloe instead. Convinced the Blur is Jor-El, Zod enlists Tess’s help in finding him to force him to reveal the secret to his powers. Clark realizes Jor-El is alive and on Earth and races to find him before Zod does.

In an attempt to cheer up Clark, Lois convinces him to attend their five-year high school reunion. A visit back to the home of the Crows has Clark remembering old times with Lana and Chloe, while Lois is furious that no one remembers her five days as a student. Brainiac 5.0 uses his Legion ring to visit from the future and takes Clark through his past, present and future. He shows Clark what really happened the night Jonathan died, Oliver’s current pain and Clark’s future at the Daily Planet with Lois and his role as Earth’s favorite red and blue superhero.

Clark is shocked to find a mirror box in the barn. Clark Luthor surprises him and sends Clark Kent back to the alternate reality where Clark runs into a very angry Jonathan Kent. Meanwhile, back in our reality, Clark Luthor visits Tess and tells her that if she doesn’t side with him he’ll kill her. Lois asks Emil to help her bring Clark back.