Don Whitehead is a writer for Smallville.
- Lara (directed by James Conway) - Clark learns Kara is in Washington D.C. searching for the blue 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. Clark arrives in time to save her but, after searing the machine with heat vision, he also falls victim to the serum and sees what Kara sees: his mother.
- Persona (directed by Todd Slavkin) - 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.
- Traveler (Teleplay) (directed by Glen Winter) - 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. Chloe takes Kara to the Fortress and begs Jor-El to restore her memory as she is the only one who can save Clark
- Descent (directed by Ken Horton) - The secret of Veritas leads Lex in a dangerous direction that will put Clark and Lex in each other's crosshairs. There is a major power struggle and Lionel dies.
- Arctic (directed by Todd Slavkin) - 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. Chloe is arrested by the Department of Domestic Security and Lana awakens from her comatose state. Meanwhile, in an epic turn of events, Clark and Lex face off in the Fortress and Lex learns Clark’s secret.
- Plastique (co-written with Holly Henderson, directed by Rick Rosenthal) - It's Clark's first day at the Daily Planet with Lois, and the pair are immediately thrown together on a story when a bus explodes outside the office. Clark rescues Bette, a young girl who bonds with Chloe over their shared meteor abilities, but Bette is hiding a big secret. Paramedic Davis Bloome arrives in Metropolis and is drawn to Chloe.
- Abyss (co-written with Holly Henderson, directed by Kevin Fair) - Brainiac begins removing Chloe´s memories one by one until the only person she remembers is Davis. Clark realizes the only way to stop Brainiac from taking over Chloe's mind is to rebuild the Fortress of Solitude and ask Jor-El to heal her.
- Requiem (co-written with Holly Henderson, directed by Michael Rohl) - An explosion at LuthorCorp kills all the Board members and injures Oliver, who was there to announce the merger of his company with LutherCorp. Oliver believes that Lex is responsible for the blast, but Clark and Lana learn that the bomber is Winslow Schott, a toymaker and former Queen Industries employee with a grudge against Oliver.
- Metallo (co-written with Holly Henderson, directed by Mairzee Almas) - After being struck by a truck, John Corben wakes up alone in an abandoned apartment as a man-machine with a kryptonite heart. Corben realizes he now has superhuman strength and sets out to exact revenge on the Red-Blue Blur, who he perceives to be an irresponsible vigilante. Against Clark's wishes, Lois involves herself in the Red-Blue Blur's investigation, and winds up getting kidnapped by Corben.
- Crossfire (co-written with Holly Henderson, directed by Michael Rohl) - Oliver tries to help a young street girl, Mia Dearden, get out of her dangerous life by offering to train her, but Mia double crosses him. Lois asks Clark to help her land a job as an on-air television host, but the two are shocked when the station wants to hire them as a team.
- Charade (co-written with Holly Henderson, directed by Brian Peterson) Lois investigates the early prison release of ex-District Attorney Raymond Sacks but he threatens her with a gun when confronted. The Blur saves her, but is captured on film by a delivery guy who plans to sell the photo to Sacks. Lois and Clark each attempt to thwart the delivery of the photo and run into Maxwell Lord, a wealthy tycoon and Checkmate operative, who is trying to learn The Blur's identity to eliminate him. Meanwhile, Chloe discovers Zod's secret.
- Lazarus (co-written with Holly Henderson, directed by Kevin Fair) (season premiere) - Lois finds Clark's lifeless body and removes the blue kryptonite enabling him to heal himself. Lois sneaks away before Clark fully awakens in order to protect his secret. Chloe is desperate to find Oliver, so she turns to an unlikely source for answers. Jonathan returns to the Kent Farm with a message for Clark saying that "something dark is coming", and Tess awakens at Cadmus Labs, where she discovers that before Lex Luthor died, he cloned himself to harvest the organs and body parts of his clones so he could heal himself after being severely injured in the Arctic Circle.
- Ambush (co-written with Holly Henderson, directed by Christopher Petry) - The General and Lucy Lane decide to drop in on Lois and Clark for a surprise Thanksgiving dinner. Clark and the General get off to a rocky start after Lois' father bashes the superheroes and tells Clark he is trying to pass a vigilante registration law. Meanwhile, in an effort to stop the vigilante registration act from being passed, Rick Flag lies to Lucy in order to lure Clark away from the farm long enough for him to assassinate the General. Lois is torn between making her father proud and her love for Clark.
- Beacon (co-written with Holly Henderson)
- Don and writing partner Holly Henderson are real-life husband and wife.