Lucy Lane, Lois’ younger sister, comes to Smallville but Clark catches her stealing money from the Talon to pay off a European crime syndicate. Lex offers to help but everything is not what it seems. Meanwhile, a thief breaks into Lana’s apartment and steals the crystal, and Jason suspects Lionel.

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.

Lois accidentally hits a dog and brings it back to the farm to heal, but Clark quickly realizes it has super-strength. He investigates and discovers it was part of an aborted LuthorCorp experiment…and that robbers are using the dogs to help them steal money. Meanwhile, Lana wonders what Jason is up to with his mother, and Jason is forced to ask Genevieve a few questions of his own.

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 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.

Alicia (from “Obsession”) is supposedly cured and returns to Smallville to start things back up with Clark. When she pushes for more and he turns reluctant, Alicia expoess him to red kryptonite, and the two go off to Las Vegas to get married. Meanwhile, Lana questions whether sex may prove the key to winning Jason back.

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.

Lex is accused of killing a young woman and and Clark turns to Lionel for help. Meanwhile, Lana has a dream of her ancestor and a mysterious second woman – a dead ringer for Jason’s mother Genevieve, who arrives to visit her son and his new girlfriend.

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.

Mikail Mxyzptlk, a foreign exchange student and bookie, has the power to control others and uses it to sabotage football games, including the one Clark is quarterbacking. Clark and Chloe figure out his secret, but he threatens to kill Chloe unless Clark throws the next game. Mikail came to Smallville via LuthorCorp, and Lex will do almost anything to learn his secret.

Clark is drawn to the state penitentery by one of the kryptonian crystals, which Lionel is using to switch bodies with Lex. Clark intervenes and Lionel enters his body instead. While Lionel uses his newfound super-powers to regain his lost fortune and alienate Clark’s friend, Clark must convince his parents that he is the “real” Clark and reverse the processs, while avoiding murderous convicts.

Jonathan’s wallet is stolen by a super-speed thief, Bart Allen, who is faster then Clark. Bart comes to the farm and becomes friends with Clark, but Bart returns to crime when he sees an ancient manuscript that Lex has. As Clark soon realizes, the manuscript holds a map to one of the kryptonian crystals and he must go up against Bart to recover it.

Clark decides to join the football team over Jonathan’s wishes and gets the starting quarterback position when his predecessor attacks Jason over a girl. Clark and Lois investigate and discover that the cheerleaders are using kryptontie in the team’s water supply to turn them into obedient mindless boyfriends.

Abigail, an ugly high school girl, gets plastic surgery from her surgeon-mother to boost her popularity. However, her beauty hides a dark secret – when she kisses someone they’re inflicted with life-threatening hallucinations. When Lana sees Abigail with one of her victims, she becomes the next target.

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.

Clark returns to Smallville as Kal-El – intent on fulfilling his destiny, he goes after a powerful kryptonian crystal that Lex has obtained in Egypt. Meanwhile, newcomer Lois Lane arrives in Smallville to look into the death of her cousin Chloe, and Lana returns from Paris with a new boyfriend. Jonathan lies in a coma after the events of last year’s season finale and Lionel must deal with his new life in prison.

Kara, a beautiful superpowered girl from Krypton, entices Clark to join with his father and embrace his destiny. Clark is left without support after Pete’s departure when Jonathan reveals the deal he made with Jor-El. At the same time, Clark’s relationships with Lex and Lana take unexpected turns, leaving him with no one but Kara to turn to.

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.

Jeremiah Holdsclaw, a young Kiwatche Indian, steals a mythic knife from the tribal caves and gets superpowers similar to Clark’s. Jeremiah believes he is the fulfillment of the ancient prophecy of Naman, “the man who fell from the stars.” He sets out to kill Lionel with the knife, and Clark must stop him without revealing his own secret.

Believing that key information about his father’s past was lost when his memory was erased, Lex decides to join an experimental program with Dr. Garner to regain the information so he can turn his father over to the FBI. Knowing that Lex will discover his secret if he regains his memory, Clark tries to stop him but is caught by Lionel and the doctor and exposed to the same radical treatment so that Lionel can solve the mystery of Clark’s past.

When Chloe accidentally inhales a mysterious krypto-gas, she discovers it acts as a truth serum to anyone who comes in contact with her and decides to take advantage of her new power by going to the Kents to find out Clark’s secret. However, her new power comes with fatal consequences and Clark must find an antidote before she discovers the truth about him or worse, dies.

When Jonathan begins to act strangely, Clark believes Jor-El is sending Jonathan messages through the key and is the cause for his father’s withdrawal from the family. Clark goes down to the caves to confront his biological father but Lionel catches him there and begins putting the pieces together, leading him straight to Dr. Swann. As the two billionaires face off, a deal is struck and Lionel’s true motives are revealed.

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.

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 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.

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 discovers that his schoolmate Jordan can foresee the future, but is horrified when Jordan tells him he “sees” Lana dying in a fire in the next few days. Meanwhile, suspicious of his behavior, Chloe investigates Adam’s background and discovers some disturbing news.

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.

Attempting to stop a robbery, Clark is temporarily blinded when he shoots off a burst of heat vision that is accidentally reflected back into his eyes by a piece of kryptonite and soon realizes his body has developed super-hearing to compensate for his lack of sight. However, as it was in the beginning with his other gifts, Clark doesn’t quite have his new power under control.

Three of Clark’s former opponents approach Lex to enlist his help in luring Clark to the hospital after they hear that Lionel has requested Lex be given electroshock therapy to erase his memory. However, the plan goes awry when the villains double-cross Lex and use kryptonite to steal Clark’s powers. Meanwhile, Lana meets a mysterious stranger in the hospital.

Lex locates Morgan Edge and gets him to admit to dirty dealings with Lionel, but before Lex can take it to the authorities, someone tries to kill him at the mansion. Barely surviving, Lex flees and asks Clark for help. However, when Clark returns to the mansion to investigate he finds nothing amiss, and begins to wonder if it really happened, especially after Lionel announces Lex has had a psychotic break and must be institutionalized.

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.

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.

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 dreams he is being pursued by a frightened young girl who needs his help. However, after he discovers she is actually a comatose neighbor who should have woken up years ago, he enlists Lana’s help to uncover the truth – which puts Lana in grave danger. Meanwhile, Lionel demands that Lex undergo a full psychological evaluation before he hires him.

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.

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.

Under the influence of red kryptonite, Clark is following a life of crime in Metropolis while his friends and parents desperately try to find him. Lex is forced to confront his personal demons on a desert island, while Lionel holds a funeral for his presumed-dead son. And Jonathan Kent must pay a high price for the power necessary to bring his son back home.

A sense of foreboding surrounds Smallville as Clark must choose between staying with Lana and his family or fulfilling his destiny to rule the Earth. Lex and Helen prepare for their marriage, and Chloe considers Lionel’s offer to investigate Clark.

Dr. Walden comes out of a coma with super-powers and a desire to kill Clark, piquing the Luthors’ interest. The spaceship starts talking to Clark, and Helen and Lex prepare for their wedding.