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

Clark and Martha are both visited by Jonathan's ghost, who warns them about Lionel and claims that Clark must kill him to stop him. Meanwhile Fine will do whatever it takes to get the vaccine from Lex.

Clark saves a man who in gratitude decides to help Clark in return...by using his ability to turn invisible and his skill as a hitman to kill Lex so Clark can reunite with Lana. And Clark and Lana finally square off about Lana's new re...

Lionel is taken hostage by a masked man who forces him to play elaborate games for the prize of staying alive. Martha goes to confront Lionel after Clark tells her Lionel knows his secret and becomes a part of the game herself, fighting for...

Clark befriends a little girl who has the ability to telekinetically shatter glass, then comes to her aid when it's believed she killed her mother in a brutal stabbing attack. Meanwhile Lex and Lana grow closer together and Chloe finds...

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...

Clark is hypnotized by a woman who uses a supposedly magical charm to control others - he reveals his super powers and is sent to kill Lex. Meanwhile, Lex has tracked down the missing Professor Fine and plans to confront him, unaware that C...

Clark finds himself up against Lex when he befriends Victor Stone, a half-machine, half-human subject who escapes from LuthorCorp with the aid of a sympathetic doctor.

Chloe is possessed by the spirit of a young girl whose body is sealed in the Talon's walls, and goes searching for the girl's killer while Clark and Lois try to track her down.

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. M...

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.

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.

The Senatorial race between Jonathan and Lex heats up when Jonathan receives an anonymous threat warning him to drop out of the election. When Clark finds Jonathan badly beaten he determines to find the attackers. Lois is thrown into the mi...

Lex considers whether to turn an operative loose to obtain or fake damaging information against Jonathan to upset his Senatorial race. But when Lex is shot, he falls into a coma and is visited by the ghost of his mother, who shows him what ...

When Martha comes down with a strange disease, Professor Fine convinces Clark that Jor-El is responsible and that the Fortress must be destroyed to save her life. But Professor Fine has an ulterior motive which comes to fruition when they a...

Clark gives into paranoid delusions brought on by exposure to new "silver" kryptonite, and Professor Fine is the only one who can save him...before he kills Lana.