Lana has a new stalker - a boy imprisoned in his basement by his parents who sneaks out at night to visit her. Meanwhile Lionel hires Clark's mother as his personal assistant.

Lex recovers his long-lost brother Lucas and uses him in a ploy to buy out his father's share of the company. But it soon becomes clear that Lucas isn't to be trusted, and Lex soon finds himself ousted from his own company.

Clark gives up the ring and its effects rather then kill his father, and both he and the rescued Lex return to Smallville. Clark must deal with crime lord Morgan Edge, who has followed him to Smallville, while Lex must determine who tried to have him killed - Lionel or Helen.

Clark discovers that Jor-El was on Earth forty years ago. Lana's great uncle, who was convicted of murdering his wife forty years ago, shows her a picture of the man he believes really killed her aunt, and she is shocked to discover the drifter looks just like Clark. Sure that the man is Jor-El, Clark's investigation leads him to a kryptonian medallion that allows him to see bits of the past - and the life that Jor-El started for him long before he arrived on Earth.

Clark and Lana each make an attempt on Chloe's life for unknown reasons after they receive a mysterious e-mail from the Summerholt Institute. Clark must discover the source of these e-mails after Chloe reveals she has uncovered proof that they are doing mind-control research at the lab and realizes they must be trying to kill her in order to prevent her from writing an expose. Meanwhile, Lana decides to rent the apartment above the café to Adam even though she feels he is hiding something dangerous about his past.

Clark receives a panicked call from Lana and hears a gunshot before the line goes dead, but when he arrives at the Talon he is stunned to discover she is alive and well. Clark realizes the phone call came from the next day and that Adam is the one who will shoot Lana.

Clark decides to tell Lana his secret so they can finally be together. Meanwhile, an errant FBI agent kidnaps and tortures Pete to try and force him to reveal Clark's secret. Also, Lex panics after the FBI gives him 24 hours to turn over information on his father or face jail time, but help arrives from an unexpected source.

After discovering that Chloe's body isn't in her coffin, Clark and Lois Lane investigate but are stopped by Lois' father, General Sam Lane. They believe General Lane knows more then he's telling, and figure out he's been in contact with Lex. Meanwhile, after Lana's sudden departure Jason follows her to Smallville. And Lionel sends a mutant killer to determine if Chloe is alive and kill her for sure.

A Luthorcorp experiment is released into the atmosphere - a toxin that causes its victims to hallucinate their worst fear. Chloe, Clark, Lana, and Jason all fall fictim to the toxin, and Lex, desperate to find a cure, takes a dangerous antidote. Meanwhile, Lionel is released from prison and his conviction overturned thanks to a mysterious benefactor.

After Clark receives a message from the recently-deceased Dr. Swann, he and Lana follow Jason and Lex to China in search of one of the kryptonian crystals. Lana is tortured, causing Isabelle to emerge and wreck havoc in her search for the crystal.

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.

Clark must stop the school photographer after he sets up a fake high school and uses his ability to petrify people to kidnap students - including Chloe and Lana - to keep the glory days of high school going forever. Meanwhile, Lex and Lionel are kidnapped and tortured by the Teagues in an effort to find the Kryptonian artifact, revealing that...Lana has it.

A krypto-mutant, Gabriel, hacks into missile codes and prepares to eliminate krypto-mutants in Smallville once and for all. A powerless Clark confronts him and is shot, and only Jor-El can save him.

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 reveals his secret to Lana, Jonathan and Lex learn the results of the senatorial election, and there is a tragic car accident on the highway that takes the life of someone Clark loves, forcing Clark to appeal to Jor-El for help.

Professor Fine has unleashed a virus that will kill millions. Clark must put a stop to him, while Lex wonders what happens when he will tell Lana his newest secret.

The mysterious Green Arrow steals a necklace from Martha, and both Lois and Clark resolve to find out who the vigilante is. While Clark determines Green Arrow's true identity, Lex continues his investigation of the mysterious black box while Lionel warns Lana against him.

A Daily Planet gossip columnist uses her special power to overhear a conversation between Lana and Chloe, and publishes the conversation... where Lana admits having doubts about marrying Lex. While Chloe investigates the reporter, Lois asks Clark to help her investigate the mysterious Green Arrow bandit when she suspects he may be Oliver Queen in disguise.

Clark is once again exposed to red kryptonite, and his "other self" goes on a rampage of sorts on Valentine's Day, kissing the women he's most attracted to and expressing his uninhibited feelings for the various relationships around him.

Clark has second thoughts about Lana marrying Lex, and Lana has the same concerns. Meanwhile, the doctor involved in the secret behind Lana's pregnancy threatens Lex with his knowledge.

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.

During Clark's battle with the last Phantom Zone wraith, Lex is rescued by a mysterious woman. She then goes to the Kent farm and reveals she is Clark's cousin, Kara, from Krypton.

Lana absorbs Clark's powers during a lightning storm, which she uses to break into Lex's safe and steal some incriminating evidence. After being turned away by Grant at the Daily Planet, who won't accept her stolen evidence, Lana goes after Lex herself. Clark tries to rescue Lex, but must first battle the super-powered Lana.

When Green Arrow's band of heroes thwarts his efforts once too often, Lex employs a super-powered vigilante to take down the Emerald Archer.

Clark must learn a new superpower as he and Kara join forces to take on Brainiac, putting the lives of their friends in danger.

Clark believes a recent attack in a theater may be the work of a serial killer; Davis fears that his blackouts could mean that he is the killer.

Tess tries to kill Davis by blowing up his truck. However, after he escapes, she realizes she needs help to destroy him and turns to Clark. Tess reveals Davis' secret childhood with the Luthors and hints that she knows Clark's true identity. Meanwhile, Davis runs to Chloe for help.

Oliver tells Clark he must kill Davis, as Doomsday is a serious threat and must be stopped at all costs. However, Clark struggles with taking a human life, so the Green Arrow and his team decide to take matters into their own hands. Lois takes on Tess, but the fight takes a shocking turn. Meanwhile, Chloe gets caught in the middle of Oliver and Clark’s battle over killing Davis.

Clark tells Jor-El he’s ready to start his training, but Jor-El sends him back to Metropolis to cut ties with Lois before he can begin. Chloe is shocked when Lois suddenly reappears after having been missing for weeks, but Lois has no recollection of vanishing into thin air with the Legion ring. Chloe begs Clark to use the Legion ring to go back in time to save Jimmy, but he refuses, driving a wedge into their friendship. Meanwhile, Zod arrives at the Luthor mansion...

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.

The story of Clark Kent culminates in this epic two-hour series finale as Clark takes the last step to becoming the Man of Steel.