Lex and his girlfriend, Victoria, are attacked by an invisible entity. Suspicion falls upon the Palmer family, who are caretakers at Lex's mansion. Chloe believes that daughter Anna Palmer is responsible because of her jealousy of Victoria.

At Smallville High School, a swimmer mysteriously ages and dies after meeting his girlfriend Chrissy Parker. The new principal Reynolds arrives and comes into conflict with Clark Kent because he is a friend of Lex Luthor's. Clark asks Chloe and Pete to investigate Principal Reynolds' history, as well as Chrissy whom they suspect is a life-draining freak who needs three youths to stay eternally young every 12 years. Meanwhile, the Kents are having financial problems and Martha contacts her estranged father, whom she hasn't seen for twenty years, to borrow some money, much to Jonathan's disapproval. Lana Lang also finds an old picture of her mother with an apparent boyfriend. After not getting any help from Aunt Nelle, Lana then asks Lex to help her investigate.

It's almost graduation, and that means it's time for the prom. After a car accident, a meteor-infected student in-the-run for Prom Queen starts body-swapping. Meanwhile, a dead body is found on Lex's mansion grounds.