After Lana is almost assaulted by a college student, Clark injures the boy while helping her. When the Kents are sued for damages that could cost them the farm, Clark tries to find a way out of the lawsuit. Meanwhile, Helen's obsessive ex-boyfriend comes to Smallville to win her back but when she turns him down, he stabs her, prompting Lex to take the law into his own hands.

Clark runs up against super-strong robbers who are apparently tied to LexCorp. And Chloe begins to ally with Lionel, while Lana and Henry Small bond.

Lana is haunted by the ghost of a dead friend, Emily, but the "spirit" has connections to Lionel Luthor, who is also scheming to get control of the Indian caves and "help" Lex with his wedding.

Clark discovers someone is hunting people affected by the kryptonite rocks and the killer's next target is Lex. Clark uses his powers to save Lex, but is caught off guard when the killer learns his weakness and shoots him with a kryptonite bullet.

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.

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 is suspicious when Lana suddenly becomes attracted to a fellow student and begins to act rebelliously, which eventually lands her in jail. Clark's suspicions are confirmed when he discovers Lana's new boyfriend has magnetic powers that can move objects and alter human emotions, but when he tries to free Lana from the paranormal hold that is controlling her, she tries to kill him. Meanwhile, Lex discovers Chloe has been delving into Lionel's past and tries to get her to join forces against his dad.

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.

Clark is forced to use his powers in front of Alicia, a new girl at school, but he is surprised to find out she has powers of her own. The two develop a bond through their shared secret, but things turn ugly after Alicia becomes obsessive about sharing Clark with anyone else - especially Lana. Meanwhile, Lana asks Lex to investigate Adam.

While his father is awaiting surgery, Clark befriends a young boy, Garrett whose brother Vince just died from liver failure. However, everyone is shocked when Vince shows up alive and seemingly well - until his liver starts failing again. In a desperate attempt to keep his brother alive, Garrett straps a Kryptonite bomb to himself and demands that Vince be given Jonathan's liver or he will blow up the building.

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.

When a mysterious killer strikes at both Lana and Jason, Alicia is the leading suspect and even Clark comes to doubt her innocence. Feeling betrayed, she secretly tricks Clark into revealing his powers in front of one of his friends. And Genevieve returns to town with an offer for Lex, who in turn has an offer for Jason.

On the eve of the Smallville High School Prom, stuck-up candidate for Prom Queen Dawn Stiles is pulled into a coma when she is involved in a car crash into a ravine filled with dozens of chunks of kryptonite. While her body lies in a coma, Dawn finds her spirit allowed to possess the bodies of others, where she can continue her quest to become Prom Queen. As a result, Martha, her body possessed by Dawn, flirts with Clark and asks him to the Prom, Lana attempts to electrocute the ex-boyfriend who dumped Dawn, Lois goes all-out to ensure she and Clark go to Prom together, and Chloe attempts to set fire to the school on Prom night.

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.

Checking out a crater in a cornfield, Clark and Lana discover a baby with no parents and take him back to the Kent farm. However, when the baby, Evan, ages from a newborn to a 7-year-old in less than a day, it becomes clear he is aging at a rapid rate and they turn to Lex for help. Meanwhile, Genevieve suspects Lex has the Chinese Kryptonian artifact and orders Lionel to either recover it...or risk putting Lex in danger of his life.

Jor-El strips Clark of his powers, making him human. Delighted to finally be normal, Clark pursues a relationship with Lana sans secrets. However, after Lana, Jonathan and Martha are taken hostage by three thugs, Clark must figure out how to save his family without his super powers.

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.

Lex and Lana are at the mercy of a deranged Smallville deputy who plans to keep them captive until Lex reveals the location of the Kryptonian spaceship. Meanwhile, the Kents can't see eye-to-eye on campaign financing.

When Clark wonders if the world would be better off if he never came to Smallville, Jor-El shows him what life would have been like if he had never existed.