Lois' (Erica Durance) younger sister, Lucy (guest star Peyton List), with whom Lois doesn't get along, comes to town and charms everyone she meets. However, Clark (Tom Welling) discovers a darker side to Lucy after he catches her stealing money from a bar and forces her to reveal the truth about her sudden appearance in Smallville, a truth that puts Lois in grave danger. Meanwhile, the crystal disappears from Lana's (Kristin Kreuk) apartment and Jason (Jensen Ackles) accuses Lionel (John Glover) of stealing it.