Season 7

Episode 1: Bizarro

Clark (Tom Welling) 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.
Lex (Michael Rosenbaum), having just been arrested for Lana's (Kristin Kreuk) murder, is submerged under water in a patrol car, but is saved by a mysterious young woman.

Episode 2: Kara

Clark and Lois (Erica Durance) discover Kara's (Laura Vandervoort) 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. Despite Kara's appearance, a despondent Clark decides that without Lana there is nothing keeping him in Smallville, and heads to the Fortress of Solitude to begin his training as a superhero.

Episode 3:  Fierce

Kara (Laura Vandervoort) desperately wants to make friends and fit in on Earth, but Clark (Tom Welling) 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 (Eva Marcille), Carly (Elisa King) and Tempest (Christine Chatelain) - three meteor-infected vixens who plan to use their powers to steal a treasure map to the hidden Smallville time capsule.

Episode 4: Cure

Chloe learns that a doctor, Dr. Curtis Knox (Dean Cain), 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. Knox has a nefarious plan to kill his patients and harvest their organs.

Episode 5: Lara

Clark learns Kara is in Washington searching for the crystal. Kara is captured after she breaks into the lab and sedated with a kryptonite-infused truth serum.
The serum causes her to relive a prior trip to Earth when she followed Clark's biological mother, Lara, to the Kent farm.

Episode 6: Action

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, Rachel Davenport (guest star Christina Milian) takes off in stunt car with cut brakes, Clark must step in to stop the runaway car.

Episode 7: Wrath

Kryptonite and high voltage mix during a lightning storm, causing Lana to absorb Clark's powers.
Using her newfound super powers, she breaks into Lex's (Michael Rosenbaum) safe and steals incriminating evidence which she then delivers to Lois and Grant, demanding they run a story exposing Lex's secrets.

Episode 8: Blue

Clark hears the voice of his biological mother, Lara (guest star Helen Slater), calling for help from Kara's crystal and decides to release her, despite Jor-El's warnings.

Episode 9: Gemini

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 (guest star Tim Guinee), who was infected with an alien substance.

Episode 10: Persona

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 (guest star James Marsters) and Bizarro sets off to find him.

Episode 11: Siren

While secretly working for Oliver (guest star Justin Hartley), Chloe intercepts one of Lex's project files, but she is attacked by the Black Canary (guest star Alaina Huffman), a mystery woman with a subsonic cry. Dinah Lance, Black Canary's alter ego, is a conservative talk show host who is working at the Daily Planet and clashes with Lois.

Episode 12: Fracture

Lois follows Lex to Detroit and discovers he has found Kara who has amnesia. Finley (guest star Corey Sevier), a busboy who is obsessed with Kara, fears Lex will take her away, so he shoots Lex and holds Kara and Lois captive. After Lex's comatose body is found, Chloe offers to heal him, but Clark refuses to let her.

Episode 13: Hero

Kara and Jimmy (Aaron Ashmore) attend a "One Republic" concert and one of the roadies turns out to be former Smallville resident Pete Ross (guest star Sam Jones III). Pete unwittingly chews some kryptonite-laced gum and develops super powers. Clark and Chloe are thrilled to meet up with their old friend but warn him against using his powers in public.

Episode 14: Traveler

Lionel arranges to have Clark kidnapped and held in a kryptonite-lined cell at a Luthorcorp facility.
After Chloe and Lana find a military electric probe at the farm, they confront Lionel, who throws suspicion onto Lex.

Episode 15: Veritas

Kara decides to teach Clark  how to fly in order to strengthen his chances against Brainiac (guest star James Marsters).
However, Brainiac seems to have the upper hand against the super cousins, and some of Clark's loved ones are caught in the crossfire.

Episode 16:  Descent

The secret of Veritas leads Lex in a dangerous direction that will put Clark and Lex in each others' crosshairs.
There is a major power struggle and one character dies.
Kristin Kreuk, Allison Mack, Erica Durance, Laura Vandervoort, Aaron Ashmore and John Glover also star.

Episode 17: Alarms

Clark desperately searches for Kara and Brainiac (guest star James Marsters) 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.

Episode 18: Apocalypse

Clark discovers that Kara sent messages from Krypton in the past that indicate that Brainiac (guest star James Marsters) wants to kill Baby Kal-El so Clark will not exist in the future.

Episode 19: Quest

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.

Episode 20: Artic

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.