 Laura Vandervoort joined the cast in season seven as Kara , Clark 's Kryptonian cousin . She arrived on Earth at the same time as Clark , with the mission to protect her cousin , but was stuck in suspended animation for eighteen years . In the season seven premiere , Kara is released from suspended animation and saves Lex from drowning . A brief glimpse of Kara flying into the sky results in Lex 's new obsession with finding the " angel " that saved his life . Kara eventually finds Clark , in the episode " Kara " , who informs her that Krypton was destroyed when the two of them were sent to Earth , and everyone there is dead . Clark teaches Kara to control some of her abilities , and at the same time blend into society . In season seven 's " Lara " , Kara is captured by the Department of Domestic Security and tortured , where she relives one of her early memories of visiting Earth with Clark 's mother , Lara . She realizes that her perceptions of her father were wrong and that he was as evil as Clark said . Kara and Clark work together to fight her father , Zor @-@ El , who was unwittingly released when Clark attempted to create a clone of his biological mother in the episode " Blue " . When Zor @-@ El is destroyed at the end of the battle , Kara disappears from the Fortress of Solitude . She awakens in Detroit with amnesia and none of her abilities . 
