TOXIC WASTE – A LuthorCorp experiment is released into the atmosphere – a toxin that causes its victims to hallucinate their worst fear. Chloe (Allison Mack), Clark (Tom Welling), Lana (Kristin Kreuk), and Jason (Jensen Ackles) all fall victim to the toxin, and Lex, desperate to find a cure, takes a dangerous antidote. Meanwhile, Lionel (John Glover) is released from prison and his conviction overturned thanks to a mysterious benefactor.
JANE SEYMOUR GUEST-STARS – Lex (Michael Rosenbaum) is accused of killing a young woman and suspects that Lionel (John Glover) is behind it. Lionel, whose liver has miraculously healed, claims to be a new man and aids Clark (Tom Welling) in finding the person responsible for framing Lex. Meanwhile, Jason’s (Jensen Ackles) mother, Genevieve (Jane Seymour), comes to town to visit her son and his new girlfriend. Jason suspects her motives and worries that his seemingly accidental meeting with Lana (Kristin Kreuk) in Paris might have been all a set up by his mother.
A WITCH HUNT IN SMALLVILLE – After Lana (Kristin Kreuk) reads from a spell book written in the 1600s, she, Lois (Erica Durance) and Chloe (Allison Mack) become possessed by witches that had been burned at the stake. The three witches have come back seek revenge and search for the powerful Kryptonian crystals, wreaking havoc on the town in the process. Clark attempts to stop the witches but they strip him of his powers and force him to reveal the location of the crystal he hid in the cave.
DC COMIC VILLIAN MXYZPTLK TRIPS UP SMALLVILLE – Chloe (Allison Mack) is drawn into an underground gambling ring at school run by foreign exchange student Mikail Mxyzptlk (guest star Trent Ford) and loses her savings on a football game after Mxyzptlk uses his powers to control all the players including Clark (Tom Welling). When Chloe discovers Mxyzptlk’s secret, he kidnaps her and threatens to kill her unless Clark throws the championship game. Meanwhile, Lex (Michael Rosenbaum) threatens Mxyzptlk with deportation unless he uses his powers for Lex’s benefit.
CLARK AND LIONEL SWITCH BODIES – Clark (Tom Welling) hears a painful ringing sound in his ears and is drawn to the prison where Lionel (John Glover) is being held. When he sees Lionel attempt to stab Lex with a strange glowing stone, Clark grabs for the stone causing the two men to switch bodies. Learning his new body has super powers, Lionel immediately begins wreaking havoc on Smallville. Trapped behind bars without his powers, Clark must figure out a way to get his body and powers back in order to save his friends and family.
THE FLASH SPEEDS INTO SMALLVILLE – After Jonathan’s (John Schneider) wallet is stolen, Clark (Tom Welling) super-speeds after the thief but is stunned when he cannot catch him. The thief, Bart, a.k.a. The Flash, later shows up at the farm and tries to talk Clark into leaving Smallville for a life on the road together, flexing their super powers. Meanwhile, Lex (Michael Rosenbaum) buys a priceless framed manuscript with Kryptonian symbols and Clark learns that it contains a mysterious hidden map. However, when Bart steals the manuscript from Lex, he inadvertently puts Clark’s life in danger and must make the decision whether to save Clark or himself.
PLASTIC SURGERY HITS SMALLVILLE – Clark (Tom Welling) faces a surprising new foe in the form of a shy high school girl (guest star Brianna Lynn Brown) who turns to plastic surgery to enhance her looks and boost her popularity. However, things go awry when she discovers that her Kryptonite – enhanced beauty causes harm to anyone she kisses – and she decides her next victim will be Lana (Kristin Kreuk). Meanwhile, Jason (Jensen Ackles) and Lana continue to hide their relationship from Clark.
CLARK AND LOIS INVESTIGATE CHLOE’S MURDER – Clark (Tom Welling) and Lois Lane (Erica Durance) investigate Chloe’s (Allison Mack) apparent murder, but are stopped by an army officer, General Sam Lane (guest star Michael Ironside), who turns out to be Lois’ father. Lois suspects that Sam knows more about Chloe’s death than he will admit, and Clark discovers that Sam has recently been in contact with Lex (Michael Rosembaum). Jason (Jensen Ackles) arrives from Paris and convinces Lana (Kristin Kreuk) to continue their relationship. Suspecting that Chloe is still alive, Lionel (John Glover) sends an assassin with the power to morph his limbs into metallic weapons to keep Chloe from testifying against him.