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.

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.

When Lex's Level 33.1 project comes to fruition, Oliver Queen must bring together several of Clark's "heroic" super-powered allies together: Arthur Curry, Bart Allen, and Victor Stone.

When Zod and the Kandorians launch their brutal attack on Earth, Chloe calls in some old friends to join the fight against the aliens. Clark and Zod face off in an epic battle for the control of Earth.

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.

Clark travels to New York to meet Dr. Swann, a brilliant scientist who holds a message for Clark from his home planet. Meanwhile Lana decides to move out of Chloe's house after they get into an argument about Clark.

After a nightmare, Clark goes to the cave to confront his father Jor-El. Jor-El warns that the crystals have fallen into human hands and have triggered a new meteor shower which will annihilate the Earth unless he reunites the three crystals. Meanwhile, Lex helps Lana, who has apparently commited murder, but then turns against her to get possession of her Kryptonian stone. As disaster looms, Chloe and Lois try to find Lana while Clark attempts to reassemble the stones, and Jason returns to make things unpleasant for the Kents.

Clark discovers the reason Lana married Lex then and sets out to kill Lionel. Lex tries to use DNA from the last phantom to power his super-soldiers. Lois goes to a dam to search for Lex's lab but is caught by a security guard and fatally injured. Chloe's power is discovered.

No one is safe when Lex seeks the secret of Veritas, and Clark tries to stop him.

Unexpected guests crash Chloe and Jimmy's wedding; Oliver thinks he has found Lex and sets out to confront him, but he is shocked to find Lana instead; Lois and Clark grow closer.

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.

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.

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 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.

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.

A man named Sylvester Pemberton tracks down Chloe and tells her he knows about her team of superheroes and needs their help. However, before he can explain who he is, he is attacked and killed by Icicle. Clark and Chloe's investigation leads Clark to the former headquarters of the Justice Society of America where he meets up with Nelson AKA Dr. Fate, Carter Hall AKA Hawkman and Courtney AKA Star Girl. Courtney pleads with Hawkman and Dr. Fate to help her catch the killer that is targeting their group but they are reluctant to resume their duties as superheroes. Clark, John Jones, Green Arrow and Chloe team up to help the JSA stop Icicle before he murders another member of the group. Meanwhile, Lois receives a package from a mysterious agency called Checkmate, run by Amanda Waller.

Lex is hit with a surprise after his father closes the local Smallville plant to force him back to Metropolis, blaming the plant's failure on his management. Meanwhile Clark prepares for his date with Chloe, reporter Roger Nixon gets wind of Clark's alien origins after setting up an explosion, and Whitney joins the Marine Corps. Lex works with the workers to buy the plant and put it under local management, and his father Lionel threatens to sabotage the efforts by buying up their mortgages. It all comes together when Nixon uses the "key" Lex found (in "Obscura") to activate the spaceship just as three tornados hit Smallville. He flees into the storm with Jonathan in pursuit and Martha left to confront the opening spaceship. The tornado hits Lex's manor and traps Lionel under beam, leaving Lex with a life-or-death decision to make. And Clark arrives to see Lana whisked up into the tornado. (to be continued...)

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.

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.

Having been transported to the Fortress of Solitude, Clark is confronted by Jor-El, who tells him he cannot return to Smallville, instead he must stay and prepare to save the planet. Also, transported to the Fortress, Chloe is unable to handle the sub-zero temperature and collapses, begging Clark to use his powers to save her. Jor-El forbids him to leave, but finally acquiesces, telling Clark he must return before sunset or there will be dire consequences. Meanwhile, Lana is horrified when she sees two Kryptonian aliens emerge from a spaceship discovered in the remnants of the meteor shower. The two aliens destroy what's left of the town searching for Kal-El.

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.

The Persuader attacks Clark; Chloe, as Brainiac, tells Davis he is Doomsday and that he was created to destroy the "other Kryptonian" and the world.

Clark has his first run-in with red kryptonite in this exploration of classic Superman mythology, turning immoral when he gets his high-school ring holding a piece of rock. Meanwhile, Lex and his father have some issues to resolve when Lionel starts taking over the manor.

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 powerless Clark is trapped in the "Phantom Zone" surrounded by the criminals his father imprisoned there. However, an unexpected ally comes to his aid. Meanwhile, Zod in Lex's body advances his plan to transform Earth into a new Krypton, while using Lana to produce an heir.