Obsession

S3 E14: Clark is forced to use his powers within sight of Alicia (SARAH CARTER -"Final Destination 2," "Black Sash"), a new girl at school, but he is surprised to find out she has powers of her own. The two develop a bond through their shared secret, but the situation gets ugly after Alicia becomes obsessive about having to share Clark with anyone else--especially Lana. Meanwhile, Lana asks Lex to investigate Adam (recurring guest star IAN SOMERHALDER).