Clark confronts Bizarro, the last wraith from the Phantom Zone, and the ensuing fight causes the dam to break and a torrent of water rushes towards the land.
Clark and Lois discover Kara's spaceship, but before they can open it, Kara appears and knocks Lois out. Clark is shocked after Kara tells him she is there to protect baby Kal-El.
Kara desperately wants to make friends and fit in on Earth, but Clark tells her to keep a low profile until she can get her powers under control. Despite his warnings, when the "Miss Sweet Corn" beauty pageant comes around, Kara signs up and meets the competition - Tyler, Carly and Tempest - three meteor-infected vixens who plan to use their powers to steal a treasure map to the hidden Smallville
Chloe learns that a doctor, Dr. Curtis Knox, has been treating meteor-infected people and removing their abilities. Desperate to get rid of her powers, Chloe makes an appointment to see him, unaware that Dr.
The residents of Smallville are thrilled when "Warrior Angel," a movie based on a comic book, begins shooting in town. However, after the lead actress takes off in stunt car with cut brakes, Clark must step in to stop the runaway car.
Clark learns Kara is in Washington searching for the crystal. Kara is captured after she breaks into the secret government lab and is sedated with a kryptonite-infused truth serum.
Kryptonite and high voltage mix during a lightning storm, causes Lana to absorb Clark's powers. Using her newfound super powers, she breaks into Lex's safe and steals incriminating evidence which she then delivers to Lois and Grant, demanding they run a story exposing Lex's secrets.
Clark hears the voice of his biological mother, Lara, calling for help from Kara's crystal and decides to release her, despite Jor-El's warnings. Lara and Clark reunite and she gives him Jor-El's ring, which contains blue kryptonite.
After a two week absence, Clark returns to Smallville from the Fortress and tells Lana that Kara is gone. Clark tells Lana they should team up to bring Lex down, so she gives him all the information she's gathered so far, including a report on a man named Adrian, who was infected with an alien substance.
While Clark is frozen in the Fortress, Bizarro takes over his life with Lana. Unaware she is with Bizarro, Lana enjoys the "new Clark" and shares information she's gathered on a serial killer who is draining his victims of all trace minerals. The two conclude it must be Brainiac and Bizarro sets off to find him. Lex is stunned at Lionel's reaction after Grant reveals he is a clone of Julian.
While secretly working for Oliver, Chloe intercepts one of Lex's project files, but she is attacked by the Black Canary, a mystery woman with a subsonic cry.
Lois follows Lex to Detroit and discovers he has found Kara, who has amnesia. Finley, a busboy who is obsessed with Kara, fears Lex will take her away, so he shoots Lex and holds Kara and Lois captive.
Kara and Jimmy attend a "One Republic" concert and one of the roadies turns out to be former Smallville resident Pete Ross. Pete unwittingly chews some kryptonite-laced gum and develops super powers.
Lionel arranges to have Clark captured, kidnapped and held in a kryptonite-lined cell at a Luthorcorp facility for unknown reasons. After Chloe and Lana find a military grade, kryptonite laced taser dart at the farm, they trace it to Lionel, who throws suspicion onto Lex.
After a confrontation with Braniac, Kara decides to teach Clark how to fly in order to strengthen their chances against him in the next go-round. Braniac goes after Lana, putting her in a near catatonic state which he claims is making her suffer.
The secret of Veritas leads Lex in a dangerous direction when he kills Lionel for a key that holds the secret to control Clark. Lois, Jimmy and Chloe find evidence that Lex killed Lionel and all their lives are put in danger as Lex's underling stops at nothing to protect her boss. Clark now has to stop Lex from uncovering whatever secret is held in the lock box in Geneva.
Clark desperately searches for Kara and Brainiac, as Brainiac is the only one who can reverse Lana's condition. Clark asks Chloe to check any large power surges in the area, so she breaks into several government computers, setting off alarms. Jimmy is caught between the Department of Security - who threatens him with jail time unless he helps them arrest Chloe - and Lex, who offers to help clear Chloe if Jimmy agrees to be in his debt.
Clark discovers the messages Kara sent are from Krypton are from the past and indicate that Brainiac wants to kill Baby Kal-El to erase Clark from the future.
Lex is attacked by a cloaked stranger who carves kryptonian symbols into his chest - a message for Clark. Chloe and Clark investigate and discover one member of the Veritas clan has survived and is hiding in a church, dedicated to Clark.
After killing Edward Teague, Kara tells Lex he is destined to defeat the Traveler and offers to take him to the Fortress to learn how. Clark is stunned that Kara would go to Lex but it is revealed that Brainiac is impersonating Kara and she's actually trapped in the Phantom Zone.