The school unknowingly uses red kryptonite in the class rings and its effect on Clark (Tom Welling) stuns his friends and family as he turns into a rebellious and dangerous teenager who decides to use his powers for evil instead of good. Jonathan (John Schneider) and Martha (Annette O'Toole) scramble to find the truth behind Clark's behavior before he exposes his true identity, while Lana (Kristin Kreuk) finds herself drawn to the "new" Clark who declares his love for her.