Lindsay Harrison

Lindsay Harrison was a teenage girl who went missing after the 1989 meteor shower in Smallville. 14 years later, she seemingly reappeared in town and claimed to be a Kryptonian girl named Kara.

Powers

 * Super Strength: Kara is greatly stronger than virtually anything in the universe, except Clark Kent and a few others.
 * Super Speed: Kara can move and or react at speeds that far exceed the sound barrier whether it is on land or underwater.
 * Flight: As "Kara of Krypton", Lindsay was able to fly.
 * Super Hearing: Kara can hear indirect whispers, pitches, and frequencies from vast distances away.
 * Molecular Disintegration - In addition to her Kryptonian-based abilities, Lindsay also displayed the power to disintegrate matter at the molecular level with her hands. She did this with Agent Loder's car - completely atomizing the vehicle and killing Loder instantaneously, to the point of feeling no pain.

Origins
In her youth, she was arrested for shoplifting. During the 1st Meteor Shower, she and her mother were returning to their home in Illinois when their car was struck by a meteor on Route 8 near the Kawatche Caves. Her mother was killed, but Lindsay's body was never found.

It's unknown what happened to her. Jonathan Kent speculated that she had been trapped in the Caves by Jor-El and turned into a Kryptonian. However, this was never proven.

Season 3
Kara first appears walking through the woods of Smallville at night, completely naked. She steps out onto the road and is almost hit by an incoming driver, only to smash the hood with her fists - sending the vehicle careening over her head and bursting into flames upon impact.

Casually proceeding on her path, she makes her way to the Kent Farm and presents herself to a bewildered Clark as he answers the door, introducing herself as Kara from Krypton. After the Kents provide her with clothing, Clark inquires about Krypton and her reasons for showing up.

She explains that she emerged from inside the cave walls and that it's her intention to take Clark back with her to a place where he wouldn't be alone. Jonathan, skeptical of her motives, tries to reason with her, however she shuts him down - calling Clark by his Kryptonian name.

Upon receiving some clothes, she claimed to have come from the Kawatche Caves and told the Kents she was there to take Clark home to fulfill his destiny, and warned that everyone he knows would betray him. Kara took Clark flying to the cave and revealed that she has been in the cave waiting for the time to be right. Clark declined her offer to go into a passageway to find out everything. The next day, she revealed to the family that Jonathan broke the covenant: that in return for the power he received to bring Clark home, Jonathan would return Clark to Jor-El.

As Agent Loder listened in, Kara sensed him and murdered him by disintegrating him and his car. Kara warned Clark that he and she were the last Kryptonians alive and they must preserve their race.

When Clark learned of Lex's room of obsession and after Lana left for Paris, Kara comforted Clark and promised to take him to Lara. Clark and Kara prepared to "leave" but Chloe identified her fingerprints as those of Lindsay Harrison. After she was confronted about this by Clark and Jonathan, Kara disappeared in a flash of light. According to Jor-El, she had served her purpose.

Season 7
After Clark encountered another girl named Kara, he went to the Fortress of Solitude and questioned Jor-El about her, during which he mentioned Lindsay.