- "Oh great, possessed by an evil slut." – Lana Lang, Spell
Finally free of Smallville's expectations, Clark, and the metahumans of her hometown, Lana believed she could finally start to build her own life. In Paris, she met Jason Teague, and started a relationship with him. While taking a brass rubbing of the ancient tomb of Countess Margaret Isobel Thoreaux, Lana passed out and was imprinted with a weird symbol. After discovering that the symbol was similar to the ones in the Kawatche Caves, Lana had to return to Smallville to learn more about the mysterious tattoo on her back.
As soon as she arrived in town, she learned of the death of Chloe and went to visit her at the cemetery, meeting Lois Lane in the process. After seeing Clark again, the two talked about her return, but she refused to tell him the real reason why she had returned. After talking with Lex, Lana managed to live in the Talon apartment and soon was joined by Jason who followed her from Paris to be with her.
Lana and Jason continued their relationship in Smallville, keeping it a secret because of Jason's job as the high school assistant football coach. However, when Lionel Luthor, in Clark's body, walked in on Lana and Jason making out, Lana later confronted him and Lionel (still in Clark's form) kissed her: she slapped him and stormed off. This caused her relationship with Clark to crumble especially after Jason was fired due to being accused of having a relationship with Lana.
Unable to find an answer to her tattoo, Lana researched Isobel and learned that the Countess was her ancestor and that she was burned at the stake as a witch. After she touched Isobel's spell book, Lana was possessed by the Countess. As Isobel, she placed a spell on Lois Lane and Chloe Sullivan, causing them be possessed by her two cohorts. After Clark destroyed the spell book, Lana, Chloe, and Lois returned to normal and Lana then learned that it wasn't Clark who informed the school that Jason was dating a student: it was Lex.
After being possessed by her ancestor, Lana started to have dreams where she witnesses the execution of Isobel Thoreaux and also of a woman yelling at Isobel angrily. Lana was shocked to learn that the woman of the dream looked immensely like Jason's mom and then began to suspect the real reasons that Jason had begun to date her.
Although her relationship with Jason was stable, her past with Clark still followed her and this caused Jason to begin to doubt her. Lana tried to give her virginity to Jason as a show of loyalty, but he refused. Later on, Lana was furious that Jason accepted Lex's job offer, but Jason tells her he would use this to get to more information about Lex as well as for his and Lana's research on the Countess. However, when Lex told Lana that Jason already knew everything about Isobel before they met, Lana had to reevaluate how well she knew Jason.
When Lionel informed Lana that Jason and Lex were in China together searching for one of the Stones of Power, and that Duchess Gertrude (Jason's ancestor) had been obsessed with finding the stones as well, he made arrangements for Lana to go to China on the LuthorCorp jet. Clark offered to go with her and after arriving, went to a temple where the Crystal of Air was located. Lana got captured and was taken to Jason and Lex only to be possessed again by Isobel. After having fought Clark for possession of the stone, Lana reverted to her true self and Jason managed to sneak the Crystal of Air to Smallville without Clark and Lex noticing.
Lana then decided to hide the stone from everyone else, including Jason and pretend that a thief stole the stone.
By this time, Lana felt quite confused and shocked to learn that Lex had secret feelings for her as he kisses her while being split in two. Also, she started to get closer to Clark again after feeling that he was the only one she could trust. This was discovered by Jason at the prom dance and their relationship comes to an end.
As the year ended, Lana's feelings for Clark returned. Lana and Clark discovered an abandoned baby in the cornfield and took him back to the Kent Farm, where they bonded over the foundling, whom Clark named "Evan." After Evan died, they reminisced about their time with him. Then Lana started to feel that she could be with Clark after all.
When she was attacked by Genevieve Teague, who figured out that Lana had one of the Stones of Power. Isobel once again possessed Lana, and stabbed and killed Genevieve with the Crystal of Air. After Isobel went dormant within her, Lana was given refuge by Lex. When another meteor shower was predicted to hit Smallville, Lex helped Lana leave Smallville.
Before leaving, Lana gave the Crystal of Air to Clark, feeling that only he would know what to do with it. The two confessed their love to each other and went their separate ways. Lana tried to send a message to Chloe, but was stopped by Lex, because he didn't want anyone to know what was happening. Lex got Lana into a helicopter: as they took off, Lana and the pilot dodged the falling meteors. However, one struck the tail of the helicopter and they plummeted to the ground. Though badly injured, Lana managed to survive the crash and pulled clear of the helicopter. She dragged herself to a nearby crater and pulled herself up to its edge, spotting the Black Ship, which began to open.